sci.electronics.repair - 25 new messages in 7 topics - digest

10:00 PM Penedão 0 comments

sci.electronics.repair
http://groups.google.com/group/sci.electronics.repair?hl=en

sci.electronics.repair@googlegroups.com

Today's topics:

* Orange Rocker 30, combo, 2006 - 5 messages, 4 authors
http://groups.google.com/group/sci.electronics.repair/t/fdf96ce609e107d9?hl=en
* Where to get schematic of Funai TV, Model FT1371? - 3 messages, 2 authors
http://groups.google.com/group/sci.electronics.repair/t/f75b6f935b5d3675?hl=en
* Danger of running hot receiver (Kyocera)? - 7 messages, 6 authors
http://groups.google.com/group/sci.electronics.repair/t/2eeb7d68559500c5?hl=en
* Teac AG-790 has me stumped... - 5 messages, 4 authors
http://groups.google.com/group/sci.electronics.repair/t/19f1f1c9d95691fb?hl=en
* continuous action solder sucker - 2 messages, 2 authors
http://groups.google.com/group/sci.electronics.repair/t/1447a02166d89d01?hl=en
* oops! coffee into the top of TV! - 2 messages, 2 authors
http://groups.google.com/group/sci.electronics.repair/t/927853c231d2a8d2?hl=en
* So, who's the king of finding data sheets ... ? - 1 messages, 1 author
http://groups.google.com/group/sci.electronics.repair/t/4e444c319ac55fa0?hl=en

==============================================================================
TOPIC: Orange Rocker 30, combo, 2006
http://groups.google.com/group/sci.electronics.repair/t/fdf96ce609e107d9?hl=en
==============================================================================

== 1 of 5 ==
Date: Tues, Jun 29 2010 12:24 pm
From: "Geoffrey S. Mendelson"

Arfa Daily wrote:
> Er, that would be a yes then ... Probably three or four a week, most every
> week, and have been doing them for around 40 years

If you are such an expert, please tell us how they got that volume
control to go to 11, while (whilst?) everyone knows they only go to 10?

:-)

Geoff.

--
Geoffrey S. Mendelson, Jerusalem, Israel gsm@mendelson.com N3OWJ/4X1GM
I do multitasking. If that bothers you, file a complaint and I will start
ignoring it immediately.

== 2 of 5 ==
Date: Tues, Jun 29 2010 5:43 pm
From: "Arfa Daily"

"Geoffrey S. Mendelson" <gsm@cable.mendelson.com> wrote in message
news:slrni2khtm.60r.gsm@cable.mendelson.com...
> Arfa Daily wrote:
>> Er, that would be a yes then ... Probably three or four a week, most
>> every
>> week, and have been doing them for around 40 years
>
> If you are such an expert, please tell us how they got that volume
> control to go to 11, while (whilst?) everyone knows they only go to 10?
>
> :-)
>
> Geoff.
>
> --
> Geoffrey S. Mendelson, Jerusalem, Israel gsm@mendelson.com N3OWJ/4X1GM
> I do multitasking. If that bothers you, file a complaint and I will start
> ignoring it immediately.

If I told you that Geoff, I'd be destroying my niche market. Suffice to say
that they used triodes with more than three electrodes ... d;~}

Arfa

== 3 of 5 ==
Date: Tues, Jun 29 2010 5:59 pm
From: "Phil Allison"

"Arfa Daily"
>
>> ** What planet do you live on ???
>>
>
> Apparently, a very different one from you ...

** Where reality never intrudes on you rose tinted view.

> But then, of course, I was forgetting who I was trying to have a reasoned
> discussion with.

** Shame you have not seen or MISSED the common valve amp faults I
mentioned.

Maybe Marshall, Gibson, Fender, Peavey and others ship their bad batches to
Australia deliberately or maybe you have been leading a charmed existence.

> It had completely slipped my mind that anyone who looks at anything from a
> different point of view to you, must be wrong.

** Now you are completely off with the fairies.

What you have NOT see cannot be dismissed as non existent.

> I suppose you'll start in on the hysterical abuse hurling next.

** You are supplying plenty of smug, pommy provocations for that.

> Well, if that's what you need to do, go right ahead. I really don't care.

** You don't have a case or a clue - really.

> And I suppose you know Jim all the way from upside down land do you ?

** Jim Marshall visited Australia a number of years back, did interviews
with the trade press and gave a presentation to an audience of industry folk
in Sydney.

Before Jim accepted any questions, the MC gave a stern warning to the
assembled audience that Jim was not involved in the design or manufacture of
Marshall amps and that no questions about the notoriously poor design or
appalling reliability of the amps would be allowed.

Wise move.

.... Phil

== 4 of 5 ==
Date: Tues, Jun 29 2010 6:24 pm
From: dplatt@radagast.org (Dave Platt)

In article <VqwWn.84179$_F1.18386@hurricane>,
Arfa Daily <arfa.daily@ntlworld.com> wrote:

>> If you are such an expert, please tell us how they got that volume
>> control to go to 11, while (whilst?) everyone knows they only go to 10?
>>
>> :-)

>If I told you that Geoff, I'd be destroying my niche market. Suffice to say
>that they used triodes with more than three electrodes ... d;~}

Let me guess... instead of using thorium as a dopant in the filaments
to enhance electron emission, they used quadmium, right?

--
Dave Platt <dplatt@radagast.org> AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

== 5 of 5 ==
Date: Tues, Jun 29 2010 9:59 pm
From: "Geoffrey S. Mendelson"

Arfa Daily wrote:

> If I told you that Geoff, I'd be destroying my niche market. Suffice to say
> that they used triodes with more than three electrodes ... d;~}

I figure you could get an extra 20 to 30 quid an amp if you offered to
upgrade them from a maximum of 10 to 11. :-)

Geoff.

--
Geoffrey S. Mendelson, Jerusalem, Israel gsm@mendelson.com N3OWJ/4X1GM
I do multitasking. If that bothers you, file a complaint and I will start
ignoring it immediately.

==============================================================================
TOPIC: Where to get schematic of Funai TV, Model FT1371?
http://groups.google.com/group/sci.electronics.repair/t/f75b6f935b5d3675?hl=en
==============================================================================

== 1 of 3 ==
Date: Tues, Jun 29 2010 12:30 pm
From: Robert Macy

Anybody got one lying around?

Or at least covering the PCB on the back of the CRT neck?

== 2 of 3 ==
Date: Tues, Jun 29 2010 4:17 pm
From: PeterD

On Tue, 29 Jun 2010 12:30:56 -0700 (PDT), Robert Macy
<macy@california.com> wrote:

>Anybody got one lying around?
>
>Or at least covering the PCB on the back of the CRT neck?

So you narrowed it down to that board?

== 3 of 3 ==
Date: Tues, Jun 29 2010 5:53 pm
From: Robert Macy

On Jun 29, 4:17 pm, PeterD <pet...@hipson.net> wrote:
> On Tue, 29 Jun 2010 12:30:56 -0700 (PDT), Robert Macy
>
> <m...@california.com> wrote:
> >Anybody got one lying around?
>
> >Or at least covering the PCB on the back of the CRT neck?
>
> So you narrowed it down to that board?

After starting the thread,
"oops! coffee into the top of TV!"
and not receiving any URL's for a schematic I started this one, trying
to be more specific.

The liquid ran onto the HV electrode and HV cable that physically laid
on top of a bare connection on that PCB.
Just seemed that's probably the area that got damaged.

==============================================================================
TOPIC: Danger of running hot receiver (Kyocera)?
http://groups.google.com/group/sci.electronics.repair/t/2eeb7d68559500c5?hl=en
==============================================================================

== 1 of 7 ==
Date: Tues, Jun 29 2010 12:54 pm
From: David Nebenzahl

Got someone with a Kyocera receiver (R-851, 85 w/chan.) that they say
"smells like something's burning". Don't have more specific information
than that; I'm assuming no magic smoke is visible. I'm advising them
that perhaps something (dust, etc.) is in the heat sink that's getting
heated and smelling. Apparently the output stages (MOSFET) of these
beasts tend to run on the hot side.

Question: does anyone know what kind of overcurrent or overtemperature
protection this unit has? User is concerned about "ruining" it if it is
in fact overheating (which I can't determine at this distance). They're
running it with 4-ohm speakers at not-very-high levels; I also suggested
trying it with 8-ohm speakers and seeing if the smell lessens.

Not much info to go on, I know, but I really would like to know more
about any protection circuitry in this piece of gear.

--
The fashion in killing has an insouciant, flirty style this spring,
with the flaunting of well-defined muscle, wrapped in flags.

- Comment from an article on Antiwar.com (http://antiwar.com)

== 2 of 7 ==
Date: Tues, Jun 29 2010 1:15 pm
From: "William R. Walsh"

Hi!

I'm guessing this is of a similar vintage to something like my Kyocera
DA-610 CD player (1985)?

If it is, I'd expect that you'll find it is Incredibly Overbuilt
inside. Kyocera absolutely was *not* cheap-skating on these things.

Even so, the DA-610 I found had some problems and needed some simple
R&R before it was at its best. Most of it was just age-related wear
and tear. The electronics themselves have never needed a thing, but
then again, they're not under the stress that an audio amplifier would
be.

I would at least clean the thing.

William

== 3 of 7 ==
Date: Tues, Jun 29 2010 1:20 pm
From: Meat Plow

On Tue, 29 Jun 2010 12:54:13 -0700, David Nebenzahl ǝʇoɹʍ:

> Got someone with a Kyocera receiver (R-851, 85 w/chan.) that they say
> "smells like something's burning". Don't have more specific information
> than that; I'm assuming no magic smoke is visible. I'm advising them
> that perhaps something (dust, etc.) is in the heat sink that's getting
> heated and smelling. Apparently the output stages (MOSFET) of these
> beasts tend to run on the hot side.
>
> Question: does anyone know what kind of overcurrent or overtemperature
> protection this unit has? User is concerned about "ruining" it if it is
> in fact overheating (which I can't determine at this distance). They're
> running it with 4-ohm speakers at not-very-high levels; I also suggested
> trying it with 8-ohm speakers and seeing if the smell lessens.
>
> Not much info to go on, I know, but I really would like to know more
> about any protection circuitry in this piece of gear.

If it smells of burning electronics I would strongly suggests the person
unplug the unit and get it somewhere to be looked at. Smoking the outputs
in a DC coupled amp can cascade back through driver and current control
stages in the blink of an eye and cause a catastrophic amount of damage.

== 4 of 7 ==
Date: Tues, Jun 29 2010 4:15 pm
From: Robert Macy

On Jun 29, 12:54 pm, David Nebenzahl <nob...@but.us.chickens> wrote:
> Got someone with a Kyocera receiver (R-851, 85 w/chan.) that they say
> "smells like something's burning". Don't have more specific information
> than that; I'm assuming no magic smoke is visible. I'm advising them
> that perhaps something (dust, etc.) is in the heat sink that's getting
> heated and smelling. Apparently the output stages (MOSFET) of these
> beasts tend to run on the hot side.
>
> Question: does anyone know what kind of overcurrent or overtemperature
> protection this unit has? User is concerned about "ruining" it if it is
> in fact overheating (which I can't determine at this distance). They're
> running it with 4-ohm speakers at not-very-high levels; I also suggested
> trying it with 8-ohm speakers and seeing if the smell lessens.
>
> Not much info to go on, I know, but I really would like to know more
> about any protection circuitry in this piece of gear.
>
> --
> The fashion in killing has an insouciant, flirty style this spring,
> with the flaunting of well-defined muscle, wrapped in flags.
>
> - Comment from an article on Antiwar.com (http://antiwar.com)

A bit of a reach... A 35 degree rise above ambient in a room at 68 F
feels warm to the touch, but when you run the same amp in a hot
location, room temp 90F that absolute temperature is now 125F and you
feel burnt touching it. Just like its summer here the room temp there
could be high, perhaps there is something overheating and outgassing,
for a while.

== 5 of 7 ==
Date: Tues, Jun 29 2010 4:39 pm
From: David Nebenzahl

On 6/29/2010 4:15 PM Robert Macy spake thus:

> On Jun 29, 12:54 pm, David Nebenzahl <nob...@but.us.chickens> wrote:
>
>> Got someone with a Kyocera receiver (R-851, 85 w/chan.) that they say
>> "smells like something's burning". Don't have more specific information
>> than that; I'm assuming no magic smoke is visible. I'm advising them
>> that perhaps something (dust, etc.) is in the heat sink that's getting
>> heated and smelling. Apparently the output stages (MOSFET) of these
>> beasts tend to run on the hot side.
>>
>> Question: does anyone know what kind of overcurrent or overtemperature
>> protection this unit has? User is concerned about "ruining" it if it is
>> in fact overheating (which I can't determine at this distance). They're
>> running it with 4-ohm speakers at not-very-high levels; I also suggested
>> trying it with 8-ohm speakers and seeing if the smell lessens.
>>
>> Not much info to go on, I know, but I really would like to know more
>> about any protection circuitry in this piece of gear.
>
> A bit of a reach... A 35 degree rise above ambient in a room at 68 F
> feels warm to the touch, but when you run the same amp in a hot
> location, room temp 90F that absolute temperature is now 125F and you
> feel burnt touching it. Just like its summer here the room temp there
> could be high, perhaps there is something overheating and outgassing,
> for a while.

That's along the lines of what I was thinking too.

I used to use this receiver, which ran fine for years with no noticeable
odors whatsoever. It *is* incredibly overbuilt, as someone else
mentioned here, so I'm not particularly worried about an impending
catastrophic failure.

Still would be nice to find out specifically what kinds of protection
circuits it has from someone who actually knows ...

--
The fashion in killing has an insouciant, flirty style this spring,
with the flaunting of well-defined muscle, wrapped in flags.

- Comment from an article on Antiwar.com (http://antiwar.com)

== 6 of 7 ==
Date: Tues, Jun 29 2010 4:36 pm
From: "William Sommerwerck"

My gut feeling is that the owner is simply smelling "burning dust". But he
should stop using it immediately, and have someone look it over. It might
need only a thorough vacuuming.

== 7 of 7 ==
Date: Tues, Jun 29 2010 5:52 pm
From: Cydrome Leader

David Nebenzahl <nobody@but.us.chickens> wrote:
> Got someone with a Kyocera receiver (R-851, 85 w/chan.) that they say
> "smells like something's burning". Don't have more specific information
> than that; I'm assuming no magic smoke is visible. I'm advising them
> that perhaps something (dust, etc.) is in the heat sink that's getting
> heated and smelling. Apparently the output stages (MOSFET) of these
> beasts tend to run on the hot side.

weird heatsink in that thing:

http://www.audiokarma.org/forums/showthread.php?t=246095

==============================================================================
TOPIC: Teac AG-790 has me stumped...
http://groups.google.com/group/sci.electronics.repair/t/19f1f1c9d95691fb?hl=en
==============================================================================

== 1 of 5 ==
Date: Tues, Jun 29 2010 1:01 pm
From: "William R. Walsh"

Hi!

> Twice I had asked what the function of the cap was, and
> twice you had not replied.

I am sorry about that. I must have missed seeing it.

> I assumed that as you had the service manual, and were engaged
> in fault finding to component level, that you would have sufficient
> understanding of circuit design to be able to just look at the cap on
> the schematic, and determine its function without a second
> thought.

You could say that. But I'm still *very* much in the learning phase. I
started with studying basic home appliances and household electricity
long ago. I started to study the workings of transistors,
semiconductors and other components after that. (This particular
process continues today.) Then, after much trial, I decided that I was
going to learn how to solder properly. And I finally did. My plan is
to know how to repair things even if nobody cares to. I don't plan to
do this sort of thing professionally. I'm getting there...I've built
simple electrical devices to solve problems or improve things in some
way, modified circuits, mended broken up circuit boards a few times
now and done "other stuff".

I haven't really looked into what that cap is doing...yet. I've been
very busy with many other things, including the repair of cars,
computer consulting work and "other jobs". I just haven't had the time
to sit down with the schematic and look at what's going on.

> You seem to have put this down to coincidence, and indeed, it
> may be, but from many long years of experience, it usually
> isn't.

No, I don't think it's a coincidence. I'm familiar with the concept of
more than one part being bad, and more faults surfacing as damaged
circuitry is repaired.

> Either something went wrong with the process of changing it
> - print damage, component damage, via damage, un-noticed
> solder splat, etc

Well, I'm pretty sure I didn't do any of those things. When I first
noticed the behavior change, I looked over my work very carefully. I
wanted to be sure that I had not induced this problem by my own doing.

> I don't know how much experience you have of component level
> faultfinding, but if it's not that much, don't be afraid to admit
> that.

It's probably on the lower end of intermediate, or just out of the
"total beginner" range. Of the things I've tried, though, I've had a
100% success rate...including the diagnosis of my linear tracking
turntable's front panel control failure.

> OK, no probs.

As it is, I've got enough stereo receivers, some of which I have
repaired. Maybe I have too many...at last count I'd repaired at least
four units in some way or another. One was a case of the previous
owner experiencing "operator error" so maybe it does not really count.

> It depends what they meant by "shotgunning".

This is a direct quote. Note the style as well, which has been left
intact.

"HI William.We only have what's in the manual too.Since you already
have the service manual,it shouldn't be too difficult to
troubleshot.Power supply rails o.k.?,D.C. offset?
Other than "shotgunning"parts,I don't know what else to recommend."

The power supply rails seem to be OK...they're all doing something
(don't recall the exact measurements). I wasn't sure where exactly
they wanted me looking for DC offset...I have some idea what it is,
and that's about it.

Maybe I'm reading more into it than I should be, but I take what was
written to mean "oh, we really don't repair those when one comes in
under the terms of the warranty". And maybe they don't?

I asked if there was any documentation for the error codes, or if
anyone there might know what they meant. I felt, perhaps incorrectly,
that knowing what an error code meant would help. (I do realize that
error codes are not always definitive and that they could send me
barking up the wrong tree.) I also asked if my manual was
complete...if maybe there was a piece I didn't have.

I never heard back.

I don't mind "shotgunning" parts of a circuit, but I have reservations
about doing the whole darn unit. I'd have to think whether it is worth
that to me...and I'm not convinced that it is.

> Of course, whoever was replying to you might just have
> been being facetious, and was actually suggesting that you
> stood it on a post at the end of the yard, and took a 12 gauge
> to it .... :-))

Being as it was through e-mail, I can't reliably know the intention of
what was written. I like to see the best in people, so I assume it
probably was serious.

Compared to the other receivers I have worked on, I don't think this
one is as good of a design. I may not be qualified to say that, but
then again, I did fix the others.

William

== 2 of 5 ==
Date: Tues, Jun 29 2010 1:36 pm
From: Baron

Arfa Daily Inscribed thus:

> So usually, if a manufacturer recommends "shotgunning", it's for a
> good reason. Of course, whoever was replying to you might just have
> been being facetious, and was actually suggesting that you stood it on
> a post at the end of the yard, and took a 12 gauge to it .... :-))
>
> Arfa

Thats probably what they did mean... ;-)

--
Best Regards:
Baron.

== 3 of 5 ==
Date: Tues, Jun 29 2010 2:03 pm
From: "William R. Walsh"

Hi!

> 7C26 is in reverse series with 7C27 (i.e. non-polarised'
> configuration) and I guess may be short, open or leaky?
> Change it?

I had this feeling that I should change that cap, if for no other
reason than its immediate neighbor was bad. I'd even go so far as to
say that said feeling just had something about it, telling me that I
shouldn't ignore it.

No, I'm not superstitious or anything like that. But I know when I
have a gut feeling, and I *do*.

So I'm going to do that and see what happens.

> The burning of the resistors first mentioned is indicative of an
> overload prior to the final output transistors (7V19 to 7V22).

I don't know either. The only inkling I have is that someone played it
very, very hard. (The previous owner didn't want to talk about what
happened, but I don't think they were inside it. So it's another one
of these feelings.) One channel still played without issue when I got
it.

As best I can tell, the final transistors are good.

The only thing that's really driving me batty about this is the fact
that it's a pain to do any testing, since I have to put the board back
in. I really don't want to rearrange all the internal parts for
testing purposes, because I am afraid I will lose some of them.

William

== 4 of 5 ==
Date: Tues, Jun 29 2010 2:50 pm
From: b

On 29 jun, 18:26, "William R. Walsh" <wm_wa...@hotmail.com> wrote:
> Hi!
>
> > Is it a double-sided (or worse - multilayer) pcb?
>
> No, it appears to be a simple PCB with one layer on one side.
>
> I would not call this receiver the greatest design I have seen.
> Compared to the Sherwood and Sony receivers that I have been working
> on, it strikes me as being unnecessarily complex. The main PCB is
> littered with all sorts of components where the others are much
> cleaner and simpler.
>
> William

I'd retrace my steps a bti by desoldering that last cap and checking
it out.use junk speakers just in case.
-B

== 5 of 5 ==
Date: Tues, Jun 29 2010 6:18 pm
From: "Arfa Daily"

"William R. Walsh" <wm_walsh@hotmail.com> wrote in message
news:1de39763-9576-4ab5-99f0-6730bd9359b5@d37g2000yqm.googlegroups.com...
> Hi!
>
>> Twice I had asked what the function of the cap was, and
>> twice you had not replied.
>
> I am sorry about that. I must have missed seeing it.
>
>> I assumed that as you had the service manual, and were engaged
>> in fault finding to component level, that you would have sufficient
>> understanding of circuit design to be able to just look at the cap on
>> the schematic, and determine its function without a second
>> thought.
>
> You could say that. But I'm still *very* much in the learning phase.

OK, that's fair enough. At least we now have an idea of your capabilities.
When Teac asked you to check for DC offset, they were referring to a
standing DC component at the power amplifier midpoint. This is at the
junction of 7R43 / 45 for one channel, and 7R44 / 46 for the other channel.
The voltage with respect to chassis measured at this midpoint, should be
zero. Any positive or negative standing voltage at this point, is termed a
"DC offset". If large enough, it could be damaging to a loudspeaker, so for
this reason, there is circuitry to sense any offset, and if there is one,
block a relay from operating. This relay is normally in series with the
speaker feeds. As you are hearing some hum through one channel, this would
suggest that the relay is closing (can you hear it close after a short delay
from switching on ?) and if it is, that might suggest that there was no DC
offset . But, if the protection circuit was not working correctly, it might
just allow the relay to close with an offset present. As 7C27 is in inverse
series with 7C26, I would be inclined to replace them as a pair. Your first
move though, would be to check if an offset is present on either channel.

Arfa

==============================================================================
TOPIC: continuous action solder sucker
http://groups.google.com/group/sci.electronics.repair/t/1447a02166d89d01?hl=en
==============================================================================

== 1 of 2 ==
Date: Tues, Jun 29 2010 1:23 pm
From: zekfrivo@zekfrivolous.com (GregS)

In article <4014381d-7eea-4c0c-a2c3-72bbb46f7743@y4g2000yqy.googlegroups.com>, rush14 <rush14@columbus.rr.com> wrote:
>I'm attempting to fabricate a continuous action solder sucker along
>the lines of those used at work
>

My Weller's hose is surprisingly soft. Must be more flow than suction.
It needs frequent cleaning.

greg

== 2 of 2 ==
Date: Tues, Jun 29 2010 8:36 am
From: "Dave Plowman (News)"

In article
<4014381d-7eea-4c0c-a2c3-72bbb46f7743@y4g2000yqy.googlegroups.com>,
rush14 <rush14@columbus.rr.com> wrote:
> I'm also familiar with other desoldering tools including plunger and
> squeeze bulb solder suckers, solder wick and built in suckers on
> soldering irons. I've found them all lacking in one way or another
> compared to the gizmo I'm trying to imitate from the factory.

> Any ideas from you guys about the error of my ways will be greatly
> appreciated.

You want what's known as a desolder station. They've been somewhat
overtaken by hot air devices so older ones can be picked up cheaply on
Ebay. Basically, a soldering iron with a hole through the middle of the
tip which is connected via a filter to a vacuum pump. At one time they
were fiendishly expensive. There may well be cheaper ones new from the far
east now.

--
*Beauty is in the eye of the beer holder *

Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound.

==============================================================================
TOPIC: oops! coffee into the top of TV!
http://groups.google.com/group/sci.electronics.repair/t/927853c231d2a8d2?hl=en
==============================================================================

== 1 of 2 ==
Date: Tues, Jun 29 2010 2:42 pm
From: b

On 28 jun, 00:12, Robert Macy <m...@california.com> wrote:

>
> QUESTIONS:
> 1) Any schematic for a Funai FT1371 ?
> 2) Anybody know what got zapped on the top tab of that PCB?
> 3) Assuming each video color channel is still capable, what adjustment
> to bring back color balance?

I would not advise you to make any colour balance adjustments. These
are not usually used unless to compensate for component drift with
age, or after replacement or other scenarios where recalibration is
needed; the problem here probably lies elsewhere.
Only tweak if you are sure liquid got at the pots, and even then, mark
the original position with correction fluid or a marker pen. The fact
that you have already seen the colour shift from red to green might
well mean that all is not yet dry.

Firstly try removing and reinserting the small pcb on the neck of the
tube, check to see if any liquid made it to the pins or the CRT
socket. Usually this pcb contains the RGB output IC or
transistors...how old is this TV?
-B

== 2 of 2 ==
Date: Tues, Jun 29 2010 3:36 pm
From: Robert Macy

On Jun 29, 2:42 pm, b <reverend_rog...@yahoo.com> wrote:
> On 28 jun, 00:12, Robert Macy <m...@california.com> wrote:
>
>
>
> > QUESTIONS:
> > 1) Any schematic for a Funai FT1371 ?
> > 2) Anybody know what got zapped on the top tab of that PCB?
> > 3) Assuming each video color channel is still capable, what adjustment
> > to bring back color balance?
>
> I would not advise you to make any colour balance adjustments. These
> are not usually used unless to compensate for component drift with
> age, or after replacement or other scenarios where recalibration is
> needed; the problem here probably lies elsewhere.
> Only tweak if you are sure liquid got at the pots, and even then, mark
> the original position with correction fluid or a marker pen. The fact
> that you have already seen the colour shift from red to green might
> well mean that all is not yet dry.
>
> Firstly try removing and reinserting the small pcb on the neck of the
> tube, check to see if any liquid made it to the pins or the CRT
> socket. Usually this pcb contains the RGB output IC or
> transistors...how old is this TV?
> -B

Thank you for your reply.

Should be dry. It's been 48 hours with perhaps over 30 hours of
operation. This TV being old runs a bit toasty. At the timeof the
accident, I expected the residual heat, coupled with the constant
operation since then, to be able to thoroughly dry everything out.
Also, being in California, drying is fast.

Will try that remove insert. and generally mechanically manipulate
everything. I don't think the PCB itself was washed, rather the HV
electrode wire was washed, flooding down to the bare terminal on the
PCB where very likely grounded out the HV. That's why the image
shrunk ultimately going black as the HV died. There is high
probability that the short to gnd path 'injured' low voltage
components.

White is not white, but greenish, like underwater now. I can't tell if
a color is missing, or green is simply too strong. It appears that red
is there, blue is there, green is there, flesh tones are almost ok,
but not quite. It may be that 1/2 blue is now 1/8 blue, or such. Like
very distorted transfer function. like a leaky transistor that keeps
signal very low until finally it can get turned off. And leaky
transistor would make sense with a zap going into the PCB somewhere.
It would help to have a schematic yo find out just where that
discharge entry point was.

Age? label said manufactured January 1998
Funai Model FT1371

Robert

==============================================================================
TOPIC: So, who's the king of finding data sheets ... ?
http://groups.google.com/group/sci.electronics.repair/t/4e444c319ac55fa0?hl=en
==============================================================================

== 1 of 1 ==
Date: Tues, Jun 29 2010 7:45 pm
From: "Phil Allison"

"Arfa Daily"

> The unit has a switch mode power supply (why though?)

** Lower cost and much lower weight - that PSU has to deliver over 500
watts.

> I would have thought that if you were going to bother putting a switcher
> in a junky piece of hifi that was for worldwide use, you would have used a
> design with an efficient PFC front end, that makes it universal in terms
> of input voltage.

** That only increases the expense.

The PSU in that JVC is likely to be of the unregulated kind - ie a simple
square wave inverter.

These are far preferable for audio amplifiers and cheaper to make too.

> Heaven knows, there's enough cheap and cheerful examples out there, used
> by the million in LCD TV sets.

** Irrelevant what LCD TVs use.

> Anyway, that aside, the bridge was twatted, as were two diodes?? , one
> across each of the filter caps. These devices *look* like diodes, and the
> symbol on the board is for a diode, and they're called D34 and D35, but I
> can't recall having seen diodes in this position before. Voltage sharing
> resistors, maybe. The type number on them is R4KL,

** That type is an "avalanche " diode that is specified to zener breakdown
at a particular voltage - like 200 volts.

Does two jobs:

1. It sacrifices itself and goes short to protect the electo when some
idiot does what your customer did.

2. It prevents reverse polarity current from flowing into the electro ( via
the load) during the switch on surge period - this is only an issue for 120
volt use when the circuit is acting in voltage doubler mode. Any diode with
adequate voltage an current ratings is OK for this.

.... Phil

==============================================================================

You received this message because you are subscribed to the Google Groups "sci.electronics.repair"
group.

To post to this group, visit http://groups.google.com/group/sci.electronics.repair?hl=en

To unsubscribe from this group, send email to sci.electronics.repair+unsubscribe@googlegroups.com

To change the way you get mail from this group, visit:
http://groups.google.com/group/sci.electronics.repair/subscribe?hl=en

To report abuse, send email explaining the problem to abuse@googlegroups.com

==============================================================================
Google Groups: http://groups.google.com/?hl=en

sci.electronics.repair - 25 new messages in 11 topics - digest

12:25 PM Penedão 0 comments

sci.electronics.repair
http://groups.google.com/group/sci.electronics.repair?hl=en

sci.electronics.repair@googlegroups.com

Today's topics:

==============================================================================
TOPIC: electric fence , force field B20, 2007
http://groups.google.com/group/sci.electronics.repair/t/9573289f9ec521ea?hl=en
==============================================================================

== 1 of 5 ==
Date: Tues, Jun 29 2010 12:40 am
From: "N_Cook"

8 pin SMD with blown hole in the casing. Top mark , very indistinct maybe 2
lines
0h963
0h37

maybe very stylised 4 instead of h, logo very indistinct. My first guess is
a 555 but pinning not standard
p3 ground, p8 +12V, pin 1 to a 10uF cap , other end to 0V, p5 tied to p6
goes to speed change pot with also a line from the pot to p1. No obvious
output trace.
Removed the device and internal connections between p2 and 3 presumably
fried , and also p6 and 7
Other device is a 16 pin with ident scraped off or the conformal coating
dissolved off.

In passing , a 8x5x3 mm fuse with bo encapsulation , mainly 2 bare Al plates
with something between. Working order measures 0.18R +/-.01R, marked/punched
in the Al
100
B7L
never seen anything like it before
make/series/value?

== 2 of 5 ==
Date: Tues, Jun 29 2010 2:06 am
From: "N_Cook"

== 3 of 5 ==
Date: Tues, Jun 29 2010 3:49 am
From: "N_Cook"

The fuse is surface mount , I suppose as high current draw, if only
intermittant ,it has to be quite high current, perhaps 10 amp from the 100
marking. Top face 8x5mm bent down the 3 mm over the other plate to one pad
and the other smaller plate , about 6x45mm to the other pad and some thin
material in between
of this form, polyswitch
http://www.westfloridacomponents.com/IC523PE05/40A+15V+1.9W+Resettable+SMT+P
olyswitch+Fuse+Tyco+SMD250-2.html
perhaps 10 amp version

== 4 of 5 ==
Date: Tues, Jun 29 2010 4:46 am
From: "N_Cook"

The main 14 pin SMD has no trace to 12V but p1 goes to this 8 pin SMD which
is connected to 12V so presumably some sort of current or voltage control
requiring 0 and 12V and the pot connection changes the current/V, not the
speed from "Normal" setting to "Turbo" at the top of pot range, and the
output somehow chopped or something from the 12V , smoothed by the 10uF.

== 5 of 5 ==
Date: Tues, Jun 29 2010 7:21 am
From: "N_Cook"

Those polyswitch resetable fuses may have problems in hot conditions.
Breathing on this one for 5 sec raises the 0.18R to double or so and a
soldering iron barrel switched off and cooled for 2 minutes, laid on it, is
enough to raise to kohm. Alternatively useful highly non linear thermal
sensing elements.

So far have not found a buck boost L-free version of DC to DC converter ,
step down, IC, presumably made variable via use of the pot rather than a
zener. L free version of Maxim MAX758,830,724 or 726 if anyone knows of
something that fits the bill?
This fence is stated to run on 9V as well as 12V battery so I suppose i/p 5
to 15V and output perhaps 6 to 13V or so

== 1 of 4 ==
Date: Tues, Jun 29 2010 1:49 am
From: "Arfa Daily"

"Phil Allison" <phil_a@tpg.com.au> wrote in message
news:i0bgp3$f5c$1@news-01.bur.connect.com.au...
>
> "Arfa Daily"
>>
>> If it continues to cut out, a generator, a 'scope and a meter should tell
>> all. Valve circuits are very simple and very straightforward to trace
>> signals in, and troubleshoot.
>
> ** You don't service that many valve guitar amps - do you ??

Er, that would be a yes then ... Probably three or four a week, most every
week, and have been doing them for around 40 years ... Whilst some faults
are a little obscure, most are very straightforward, and I'm sure that you
don't have any more trouble fixing them, than I do Phil. I would pick a
fault on a valve amp over a transistor one, every time, as would probably
any engineer who has ever worked with valves. Every stage is pretty much
independent, and troubleshoot-able as a separate entity. You can't say that
about most transistor amps.

>
> The ones that were originally well made are now so old they have strange
> faults most techs have never seen before - while the ones made more
> recently have designed in faults never seen before by anyone.
>
> A few examples.
>
> 1. Recent Marshall combo amps with fibreglass PCBs that become LEAKY
> when hot - output valve bias goes crazy and even the phase splitter
> stage goes way out of DC balance in normal operation because of leakage
> from anode tracks to grid tracks. There is simply no fix for this
> problem.

Care to give me a model for that behaviour ? I see a lot of Marshall combos,
as they are built just a few miles from where I live. I have not seen any
similar problems here. I used to visit Jim Marshall in his factory in the
early days. He was a very good friend of a friend of mine. As to the problem
with a - g leakage, I would have thought that you might have been able to
get away with isolating the affected tracks by cutting or even removing them
from the board completely, and then hard wiring.

>
> 2. Recent Gibson /Trace Elliot amps that develop mysterious crackling
> noises all over the circuit due to the use of water soluble flux that was
> never properly washed of the PCB. Removing the main PCB entirely and
> washing it thoroughly in solvent is the only fix.
>
> 3. Same amps as above use 9 pin PCB mount sockets that SHRINK - yep,
> the plastic material used to make the socket shrinks under the heat from
> EL84s, reducing the pitch circle diameter so much it is impossible to fit
> a new tube in the socket. Replacing all the output valve sockets is the
> only fix.
>
> Then there are all the issues with the valves themselves - all new
> production now comes from China or the former USSR and most of the valves
> have designed in faults of kinds that were never seen previously. Eg.
> nearly all 12AX7s now crackle and pop if tapped with the back of a
> screwdriver and/or have bad heater cathode hum or are very microphonic -
> while octal power types often suffer from bad soldering (PbF ?) on the
> pins causing all manner of weird intermittents when the solder joint lets
> go.

Whilst I would agree that valve quality is not as good as it was when the
likes of Mullard and Brimar etc made them, I also don't think that they are
quite as bad as you seem to find them, if you buy decent quality ones, or
manufacturer's originals, which have been vetted by the amp manufacturer as
being of the required quality. The Ruby HG (Hi Grade) 12AX7s that I use,
don't crackle and pop, and are no more microphonic than any high gain
triodes have ever been. I also don't find the h - k leakage bad either -
certainly not enough to identify as being a predominant source of unwanted
hum. And as to bad soldering on octal base pins, I honestly can't say that
I've ever seen this problem on any amp that's been across my bench, or on
any replacement valves that I have fitted, which may have had their bases
connected to the leadouts by PbF. Perhaps I've just been lucky ...

>
> Yep - fixing valve amps is pure joy.
>
>
> .... Phil
>
>

Well, I find it so ...

Arfa

== 2 of 4 ==
Date: Tues, Jun 29 2010 5:32 am
From: "Phil Allison"

"Arfa Daily"
> "Phil Allison"
>>
>>> If it continues to cut out, a generator, a 'scope and a meter should
>>> tell all. Valve circuits are very simple and very straightforward to
>>> trace signals in, and troubleshoot.
>>
>> ** You don't service that many valve guitar amps - do you ??
>
>
> Er, that would be a yes then ... Probably three or four a week, most
> every week, and have been doing them for around 40 years ... Whilst some
> faults are a little obscure, most are very straightforward, and I'm sure
> that you don't have any more trouble fixing them, than I do Phil.

** I fix them all - of course.

But there is plenty of trouble with most of them.

> I would pick a fault on a valve amp over a transistor one, every time, as
> would probably any engineer who has ever worked with valves.

** Solid state gear is far easier to fix and make stay fixed - IM long E.

>> The ones that were originally well made are now so old they have strange
>> faults most techs have never seen before - while the ones made more
>> recently have designed in faults never seen before by anyone.
>>
>> A few examples.
>>
>> 1. Recent Marshall combo amps with fibreglass PCBs that become LEAKY
>> when hot - output valve bias goes crazy and even the phase splitter
>> stage goes way out of DC balance in normal operation because of leakage
>> from anode tracks to grid tracks. There is simply no fix for this
>> problem.
>
>
> Care to give me a model for that behaviour ?

** Yep - the JCM2000: TSL100 combo series.

Easy to find many stories about the same problem on usenet and web forums.

> I see a lot of Marshall combos, as they are built just a few miles from
> where I live. I have not seen any similar problems here. I used to visit
> Jim Marshall in his factory in the early days. He was a very good friend
> of a friend of mine.

** Nice guy - who never designed or built an amp in his life.

> As to the problem with a - g leakage, I would have thought that you might
> have been able to get away with isolating the affected tracks by cutting
> or even removing them from the board completely, and then hard wiring.

** Tried that idea with the very first example I ever came across.

The PCB wound up looking like a piece of Swiss cheese and still the problem
was not cured.

The only "treatment" that helped at all was to install a fan to keep the
valves and hence PCB cooler.

Colleagues have complained to me about the exact same problem.

> Whilst I would agree that valve quality is not as good as it was when the
> likes of Mullard and Brimar etc made them, I also don't think that they
> are quite as bad as you seem to find them, if you buy decent quality ones,
> or manufacturer's originals, which have been vetted by the amp
> manufacturer as being of the required quality.

** The BAD valves are already fitted in the amps that come to me for
service.

There are NO " manufacturers originals" available in Australia AFAIK.

> The Ruby HG (Hi Grade) 12AX7s that I use, don't crackle and pop, and are
> no more microphonic than any high gain triodes have ever been.

** Yaaawwwnnnnnn.....

You compare the particular with the general.

How tedious.

> I also don't find the h - k leakage bad either - certainly not enough to
> identify as being a predominant source of unwanted hum.

** How odd then that so many new generation valve amps use DC supply for
heaters JUST because of this issue.

> And as to bad soldering on octal base pins, I honestly can't say that I've
> ever seen this problem on any amp that's been across my bench,

** What planet do you live on ???

.... Phil

== 3 of 4 ==
Date: Tues, Jun 29 2010 8:59 am
From: "Arfa Daily"

"Phil Allison" <phil_a@tpg.com.au> wrote in message
news:i0cp5t$5t2$1@news-01.bur.connect.com.au...
>
> "Arfa Daily"
>> "Phil Allison"
>>>
>>>> If it continues to cut out, a generator, a 'scope and a meter should
>>>> tell all. Valve circuits are very simple and very straightforward to
>>>> trace signals in, and troubleshoot.
>>>
>>> ** You don't service that many valve guitar amps - do you ??
>>
>>
>> Er, that would be a yes then ... Probably three or four a week, most
>> every week, and have been doing them for around 40 years ... Whilst some
>> faults are a little obscure, most are very straightforward, and I'm sure
>> that you don't have any more trouble fixing them, than I do Phil.
>
>
> ** I fix them all - of course.
>
> But there is plenty of trouble with most of them.
>
>
>> I would pick a fault on a valve amp over a transistor one, every time, as
>> would probably any engineer who has ever worked with valves.
>
>
> ** Solid state gear is far easier to fix and make stay fixed - IM long
> E.
>
>
>
>>> The ones that were originally well made are now so old they have strange
>>> faults most techs have never seen before - while the ones made more
>>> recently have designed in faults never seen before by anyone.
>>>
>>> A few examples.
>>>
>>> 1. Recent Marshall combo amps with fibreglass PCBs that become LEAKY
>>> when hot - output valve bias goes crazy and even the phase splitter
>>> stage goes way out of DC balance in normal operation because of leakage
>>> from anode tracks to grid tracks. There is simply no fix for this
>>> problem.
>>
>>
>> Care to give me a model for that behaviour ?
>
>
> ** Yep - the JCM2000: TSL100 combo series.
>
> Easy to find many stories about the same problem on usenet and web forums.
>
>
>> I see a lot of Marshall combos, as they are built just a few miles from
>> where I live. I have not seen any similar problems here. I used to visit
>> Jim Marshall in his factory in the early days. He was a very good friend
>> of a friend of mine.
>
> ** Nice guy - who never designed or built an amp in his life.
>
>
>> As to the problem with a - g leakage, I would have thought that you might
>> have been able to get away with isolating the affected tracks by cutting
>> or even removing them from the board completely, and then hard wiring.
>
> ** Tried that idea with the very first example I ever came across.
>
> The PCB wound up looking like a piece of Swiss cheese and still the
> problem was not cured.
>
> The only "treatment" that helped at all was to install a fan to keep the
> valves and hence PCB cooler.
>
> Colleagues have complained to me about the exact same problem.
>
>
>
>> Whilst I would agree that valve quality is not as good as it was when the
>> likes of Mullard and Brimar etc made them, I also don't think that they
>> are quite as bad as you seem to find them, if you buy decent quality
>> ones, or manufacturer's originals, which have been vetted by the amp
>> manufacturer as being of the required quality.
>
>
> ** The BAD valves are already fitted in the amps that come to me for
> service.
>
> There are NO " manufacturers originals" available in Australia AFAIK.
>
>
>> The Ruby HG (Hi Grade) 12AX7s that I use, don't crackle and pop, and are
>> no more microphonic than any high gain triodes have ever been.
>
> ** Yaaawwwnnnnnn.....
>
> You compare the particular with the general.
>
> How tedious.
>
>
>> I also don't find the h - k leakage bad either - certainly not enough to
>> identify as being a predominant source of unwanted hum.
>
> ** How odd then that so many new generation valve amps use DC supply for
> heaters JUST because of this issue.
>
>
>> And as to bad soldering on octal base pins, I honestly can't say that
>> I've ever seen this problem on any amp that's been across my bench,
>
>
> ** What planet do you live on ???
>
>
>
> .... Phil
>

Apparently, a very different one from you ...

But then, of course, I was forgetting who I was trying to have a reasoned
discussion with. It had completely slipped my mind that anyone who looks at
anything from a different point of view to you, must be wrong. I suppose
you'll start in on the hysterical abuse hurling next. Well, if that's what
you need to do, go right ahead. I really don't care. And I suppose you know
Jim all the way from upside down land do you ?

Arfa
>

== 4 of 4 ==
Date: Tues, Jun 29 2010 12:24 pm
From: "Geoffrey S. Mendelson"

Arfa Daily wrote:
> Er, that would be a yes then ... Probably three or four a week, most every
> week, and have been doing them for around 40 years

If you are such an expert, please tell us how they got that volume
control to go to 11, while (whilst?) everyone knows they only go to 10?

:-)

Geoff.

--
Geoffrey S. Mendelson, Jerusalem, Israel gsm@mendelson.com N3OWJ/4X1GM
I do multitasking. If that bothers you, file a complaint and I will start
ignoring it immediately.

==============================================================================
TOPIC: Notebook freezing when connected to external power supply
http://groups.google.com/group/sci.electronics.repair/t/5ce5b775904c6f5d?hl=en
==============================================================================

== 1 of 1 ==
Date: Tues, Jun 29 2010 2:37 am
From: Mike De Petris

On 8 May, 11:57, Mike De Petris <mikedepet...@gmail.com> wrote:
> On Apr 24, 9:48 pm, Mike De Petris <mikedepet...@gmail.com> wrote:
>
>
>
> > On Apr 24, 8:30 pm, Meat Plow <mhyw...@yahoo.com> wrote:
>
> > > On Fri, 23 Apr 2010 13:00:57 -0700 (PDT), Mike De Petris
> > > <mikedepet...@gmail.com>wrote:
>
> > > >I have a Toshiba Satellite A205 - S4777 that works perfect while on
> > > >battery, but the instance i plug the charger in, it freezes. First i
> > > >thought it was a Vista-Toshiba issue but only to discover that even in
> > > >BIOS it freezes instantly when the charger is plugged in. When the
> > > >laptop is off, any attempt to power it on while the charger is plugged
> > > >in, results only in a flicker of the power led.
> > > >I tried different chargers, ANY possible power options combinations in
> > > >Vista and Win7.
>
> > > >If I boot from battery and enter Windows Safe Mode, or Hiren's boot
> > > >CD, or WinXP mini all works fine even if I connect the power cord,
> > > >where normal Windows and BIOS freeze istantly.
>
> > > >I'm even thing of giving current directly by the battery contacts...
> > > >may this be possible?
>
> > > >Any help or advice on possible causes or solution to this issue would
> > > >be grateful. Thank you :)
>
> > > Uninstall the Toshiba Power Managemnt utility if you have it
> > > installed. If that fixes it try reinstalling it. If you don't have the
> > > utility installed go to Toshiba and see if it is available for your
> > > 205 and the Vista platform.
>
> > I have plain Windows 7 installed at the moment, no Toshiba nor other
> > utilities, even never connected to the network.
>
> > Anyway it freezes even in the BIOS when connecting power.
>
> don't know what more to check!

the laptop is still apart, had little time to experiment, the two
fuses are ok will have to test capacitors, in the while I took away
the cmos battery and soldered two wires to use a standard cr2032 but
nothing changes

my idea now, is that if I am not able to find the faulty component,
that may well be a custom one, I will try to cut the connections to
the battery poles and connect using a 2-way deviator, so that in one
position the lapton can work like now, charging the battery when
switched off, or running on battery only, or trun the deviator/switch
and give voltage directly to the cutted terminals, excluding the
battery, with an external power supply, the pc should still detect the
battery charge level from other contacts of battery in place

should this work?

==============================================================================
TOPIC: Discount Nike Air Max 91 Supplier (http://www.cntrade09.com)
http://groups.google.com/group/sci.electronics.repair/t/bc2ebd4690007884?hl=en
==============================================================================

== 1 of 1 ==
Date: Tues, Jun 29 2010 6:23 am
From: cntrade08

nike shoes,jordan shoes(http://www.cntrade09.com)
Air Force 1 shoes(http://www.cntrade09.com)
kids shoes(http://www.cntrade09.com)
nike air max TN shoes(http://www.cntrade09.com)
nike MAX LTD shoes (http://www.cntrade09.com)
nike air MAX 180 sports shoes(http://www.cntrade09.com)
nike air max 360 basketball shoes discount paypal (http://
www.cntrade09.com )
nike air max 2003 running shoes discount paypal (http://
www.cntrade09.com )
nike air max 97 sport shoes discount paypal (http://
www.cntrade09.com )
nike air max 95 basketball shoes( http://www.cntrade09.com )
nike air max 90 running shoes discount paypal (http://
www.cntrade09.com )
nike air max 87 fashion shoes discount paypal (http://
www.cntrade09.com )
nike Shox TL1 men shoes discount paypal (http://
www.cntrade09.com )
nike shox TL3 sports shoes discount paypal (http://
www.cntrade09.com )
nike shox NZ running shoes (http://www.cntrade09.com)
nike shox OZ basketball shoes discount paypal (http://
www.cntrade09.com )
nike shox R3 sport shoes discount paypal (http://
www.cntrade09.com )
nike shox R4 fashion shoes discount paypal (http://
www.cntrade09.com )
nike shox R5 running shoes discount paypal (http://
www.cntrade09.com )
puma shoes discount paypal
Get Nike Shoes at Super Cheap Prices
Discount Ed hardy tshirt (http://www.cntrade09.com)
Discount Ed hardy jean (http://www.cntrade09.com)
Discount Ed hardy shoes (http://www.cntrade09.com)
Discount Ed hardy handbag (http://www.cntrade09.com)
Discount Ed hardy other porduct (http://www.cntrade09.com)
Discount Nike air jordans (http://www.cntrade09.com)
Discount Nike Air Max 90 Sneakers (http://www.cntrade09.com)
Discount Nike Air Max 91 Supplier (http://www.cntrade09.com)
Discount Nike Air Max 95 Shoes Supplier (http://
www.cntrade09.com)
Discount Nike Air Max 97 Trainers (http://www.cntrade09.com)
Discount Nike Air Max 2003 (http://www.cntrade09.com)
Discount Nike Air Max 2004 Shoes
(http://www.cntrade09.com)
Discount Nike Air Max 2005 Shop (http://www.cntrade09.com)
Discount Nike Air Max 2006 Shoes Shop (http://www.cntrade09.com)
Discount Nike Air Max 360 Catalogs (http://www.cntrade09.com)
Discount Nike Air Max Ltd Shoes Catalogs (http://
www.cntrade09.com)
Discount Nike Air Max Tn Men's Shoes (http://www.cntrade09.com)

== 1 of 4 ==
Date: Tues, Jun 29 2010 6:59 am
From: "William R. Walsh"

Hi!

> So what does the cap do in the circuit ? Is it a big secret, or
> something ?

No, should it be? :-)

I don't know for certain what it does. I haven't explored it that
closely. I only noticed it being bloated out of the corner of my eye,
so I said "that should be replaced".

I've put it aside for now. Maybe another day.

TEAC has been no help. Although they did respond to my request asking
for more information, they recommended "shotgunning" the unit. (Yeah,
really.)

William

== 2 of 4 ==
Date: Tues, Jun 29 2010 9:26 am
From: "William R. Walsh"

Hi!

> Is it a double-sided (or worse - multilayer) pcb?

No, it appears to be a simple PCB with one layer on one side.

I would not call this receiver the greatest design I have seen.
Compared to the Sherwood and Sony receivers that I have been working
on, it strikes me as being unnecessarily complex. The main PCB is
littered with all sorts of components where the others are much
cleaner and simpler.

William

== 3 of 4 ==
Date: Tues, Jun 29 2010 9:36 am
From: "Arfa Daily"

"William R. Walsh" <wm_walsh@hotmail.com> wrote in message
news:4f83d666-93a0-4a06-8944-b4239971c92a@t10g2000yqg.googlegroups.com...
> Hi!
>
>> So what does the cap do in the circuit ? Is it a big secret, or
>> something ?
>
> No, should it be? :-)
>

Well, not really. I was just trying to find a way to better help you with
your diagnosis. Twice I had asked what the function of the cap was, and
twice you had not replied.

> I don't know for certain what it does. I haven't explored it that
> closely. I only noticed it being bloated out of the corner of my eye,
> so I said "that should be replaced".

Fair enough. A reasonable assumption, given the amount that's said on here
about bulging caps being at the bottom of many faults.

I assumed that as you had the service manual, and were engaged in fault
finding to component level, that you would have sufficient understanding of
circuit design to be able to just look at the cap on the schematic, and
determine its function without a second thought. It seems to me, pretty
fundamental to this process, that you know the function of the cap you have
replaced, considering that the fault symptoms changed dramatically after
replacing it. You seem to have put this down to coincidence, and indeed, it
may be, but from many long years of experience, it usually isn't. Either
something went wrong with the process of changing it - print damage,
component damage, via damage, un-noticed solder splat, etc, we've all been
there - or the fact that it was faulty before was masking some other
problem, that is now the dominant one. That was the reason that I felt it
important to know what the function of that cap is. I don't know how much
experience you have of component level faultfinding, but if it's not that
much, don't be afraid to admit that. There are plenty on here with a
lifetime's experience who will try their best to help, given the necessary
information, which ultimately helps others to learn.

>
> I've put it aside for now. Maybe another day

OK, no probs.

>
> TEAC has been no help. Although they did respond to my request asking
> for more information, they recommended "shotgunning" the unit. (Yeah,
> really.)
>
> William

It depends what they meant by "shotgunning". Once it has been determined
which stage a fault lies in, sometimes the best approach is to shotgun all
the electrolytics, or sometimes all the transistors. Semiconductors will
sometimes 'hide' their faultiness in that they've been weakened by obviously
failed nearby devices. This can - and does - result in bounced repairs,
sometimes with a cascade failure that you thought you'd successfully
repaired, repeated all over again ... :-(

So usually, if a manufacturer recommends "shotgunning", it's for a good
reason. Of course, whoever was replying to you might just have been being
facetious, and was actually suggesting that you stood it on a post at the
end of the yard, and took a 12 gauge to it .... :-))

Arfa

== 4 of 4 ==
Date: Tues, Jun 29 2010 10:37 am
From: Adrian C

On 27/06/2010 17:47, Arfa Daily wrote:

> Knowing that may be helpful to assess whether there may be an immediated
> connection between the previous and current symptoms, or whether we're
> in 'red herring' territory here ...

Well, I'm a bit bored at the moment so having a peek. :-)

The service manual is up on eserviceinfo. Page 13 is relevant.

http://www.eserviceinfo.com/downloadsm/25360/TEAC_AG-790.html

This (with the exception of the resistors) is all in output protection
past the final stage.

7C26 is in reverse series with 7C27 (i.e. non-polarised configuration)
and I guess may be short, open or leaky? Change it? What's across them
looks to be a summed fraction of the output of both L&R amplifiers, and
also a POW signal to the system micro.

The burning of the resistors first mentioned is indicative of an
overload prior to the final output transistors (7V19 to 7V22). Don't
know what that is all about, unless the amp power rails themselves have
been up to some silly voltage they shouldn't have been.

Seems enough discretes there to enjoy (!) a good troubleshoot, with
similar and isolate-able sections.

--
Adrian C

==============================================================================
TOPIC: Cheap Nike Air Force One Shoes Nike DUNK SB Shoes Nike Shox NZ Shoes
Wholesale free shipping <paypal payment>(www.24hoursneakers.com)
http://groups.google.com/group/sci.electronics.repair/t/758ef1dcfe5904e7?hl=en
==============================================================================

== 1 of 1 ==
Date: Tues, Jun 29 2010 7:06 am
From: huang

Are you searching for good quality and low price products?our company
want to be you reliable supplier in china,we offer brand
shoes,bags,jeans,clothes,we accept a variety of payment
methods .Convenient for you the more you order the better price for
you! if you interested in our goods,pls don't hestate to contact me
Our website (http://www.24hoursneakers.com/)
◥█▄▃▁
...◥█☆█▅▄▃▁▁▁▁▁▁▁▃▄▅︿@︿▅▄▁
〓▇████Ship Wholesaler█████████████▅▄▃▁▁
〓〓〓█████████████
Nike Shox NZ Shoes Wholesale(http://www.24hoursneakers.com/)
(PayPal Payment)
Nike Shox OZ Shoes Wholesale(http://www.24hoursneakers.com/)
(PayPal Payment)
Nike Shox TL1 Shoes Wholesale(http://www.24hoursneakers.com/)
(PayPal Payment)
Nike Shox TL3 Shoes Wholesale(http://www.24hoursneakers.com/)
(PayPal Payment)
Nike Shox R2 Shoes Wholesale(http://www.24hoursneakers.com/)
(PayPal Payment)
Nike Shox R3 Shoes Wholesale(http://www.24hoursneakers.com/)
(PayPal Payment)
Nike Shox R4 Shoes Wholesale(http://www.24hoursneakers.com/)
(PayPal Payment)
Nike Shox R5 Shoes Wholesale(http://www.24hoursneakers.com/)
(PayPal Payment)
Nike Shox Monster Shoes Wholesale(http://www.24hoursneakers.com/)
(PayPal Payment)
Nike Shox Torch Shoes Wholesale(http://www.24hoursneakers.com/)
(PayPal Payment)
Nike Air Rift Shoes Wholesale(http://www.24hoursneakers.com/)
(PayPal Payment)
Nike DUNK SB Shoes Wholesale(http://www.24hoursneakers.com/)
(PayPal Payment)
Nike Air Force One Shoes Wholesale(http://www.24hoursneakers.com/)
(PayPal Payment)
Nike Free Shoes Wholesale(http://www.24hoursneakers.com/) (PayPal
Payment)

== 1 of 3 ==
Date: Tues, Jun 29 2010 8:05 am
From: rush14

I'm attempting to fabricate a continuous action solder sucker along
the lines of those used at work

when repairing circuit boards. They were fast, clean, easy to use and
prevented damage to the circuit boards from excessive prolonged heat.

Unfortunately I'm now retired and the factory work has all been
outsourced overseas. There's nobody left now from work who would know
about this.

As I recall they consisted of a vacuum source (unknown to me), a
flexible hose connected to a small cylinder with a tuft of steel wool
inside to trap solder and a teflon sucking tip at the other end of
the cylinder.

Apparently there is more to vacuum technology than I imagined because
all my attempts have so far failed miserably. When I adapt a short
(~3 foot) flexible hose to my vacuum source the suction at the end of
the hose is almost non-existent.

My first attempt was using the air intake of a 12V automotive tire
inflator, an idea I got from extensive Google searching, although not
intended for that purpose. There seemed to be plenty of suction at the
air intake itself but almost no suction at the end of the flexible
hose.

I then decided to go to extremes and adapted the hose to the vacuum
port of a powerful shop vac. I actually expected the hose to collapse
from excessive vacuum but instead there was again almost no suction at
the end of the hose. I then added a secondary intake port to
alleviate what I thought might be excessive load on the shop vac then
tried using the shop vac exhaust port to create a vacuum. Neither
attempt worked.

I would normally give up but I know the theory behind it works from my
experience at the factory. I'm apparently ignorant in the physics of
vacuum.

I'm also familiar with other desoldering tools including plunger and
squeeze bulb solder suckers, solder wick and built in suckers on
soldering irons. I've found them all lacking in one way or another
compared to the gizmo I'm trying to imitate from the factory.

Any ideas from you guys about the error of my ways will be greatly
appreciated.

Thanks a bunch,
Rush

== 2 of 3 ==
Date: Tues, Jun 29 2010 8:46 am
From: "Arfa Daily"

"rush14" <rush14@columbus.rr.com> wrote in message
news:4014381d-7eea-4c0c-a2c3-72bbb46f7743@y4g2000yqy.googlegroups.com...
> I'm attempting to fabricate a continuous action solder sucker along
> the lines of those used at work
>
> when repairing circuit boards. They were fast, clean, easy to use and
> prevented damage to the circuit boards from excessive prolonged heat.
>
> Unfortunately I'm now retired and the factory work has all been
> outsourced overseas. There's nobody left now from work who would know
> about this.
>
> As I recall they consisted of a vacuum source (unknown to me), a
> flexible hose connected to a small cylinder with a tuft of steel wool
> inside to trap solder and a teflon sucking tip at the other end of
> the cylinder.
>
> Apparently there is more to vacuum technology than I imagined because
> all my attempts have so far failed miserably. When I adapt a short
> (~3 foot) flexible hose to my vacuum source the suction at the end of
> the hose is almost non-existent.
>
> My first attempt was using the air intake of a 12V automotive tire
> inflator, an idea I got from extensive Google searching, although not
> intended for that purpose. There seemed to be plenty of suction at the
> air intake itself but almost no suction at the end of the flexible
> hose.
>

My current Pace desoldering station uses a vacuum pump no larger than the
pressure pump used in a tyre inflator. My previous Weller DS900 had a
similar sized pump. On both of these stations, the vacuum port is connected
to the business end via about 2 feet of fairly soft and pliable
heat-resistant (silicone ?) tubing, about the size of TV coax. The vacuum on
both stations is as strong at the desoldering head as it is at the port, so
I'm not sure where you are having trouble with the physics of vacuum
engineering, with your attempts at replicating your work system. FWIW, there
are plenty of desoldering and rework stations on the market both new from
the Far East, and second hand on FleaBay. Most of the ones I've used work
pretty well, and in a non-production environment where there's only you, I
don't really see a need for continuous vacuum. Vacuum builds very quickly
when you operate the pump switch on a desoldering station, and is maintained
until you let go of the switch.

Arfa
> I then decided to go to extremes and adapted the hose to the vacuum
> port of a powerful shop vac. I actually expected the hose to collapse
> from excessive vacuum but instead there was again almost no suction at
> the end of the hose. I then added a secondary intake port to
> alleviate what I thought might be excessive load on the shop vac then
> tried using the shop vac exhaust port to create a vacuum. Neither
> attempt worked.
>
> I would normally give up but I know the theory behind it works from my
> experience at the factory. I'm apparently ignorant in the physics of
> vacuum.
>
> I'm also familiar with other desoldering tools including plunger and
> squeeze bulb solder suckers, solder wick and built in suckers on
> soldering irons. I've found them all lacking in one way or another
> compared to the gizmo I'm trying to imitate from the factory.
>
> Any ideas from you guys about the error of my ways will be greatly
> appreciated.
>
> Thanks a bunch,
> Rush

== 3 of 3 ==
Date: Tues, Jun 29 2010 8:46 am
From: "William Sommerwerck"

> I'm also familiar with other desoldering tools including plunger
> and squeeze bulb solder suckers, solder wick and built-in
> suckers on soldering irons. I've found them all lacking in one
> way or another compared to the gizmo from the factory I'm
> trying to imitate.

Do you really need a "continuous" device? Its only actual advantage is that
you simply hit the floor switch and "whoosh!" You don't have to reset the
plunger.

As nice as they are (and I've used them), I've never felt any strong need to
have one for occasional home use. Even if I could afford one, I wouldn't buy
one.

I have three hand-held units (two plastic EDSYNs, and an off-brand metal
unit). If a joint looks as if it's going to give me problems, I cock all of
them before I start. Solderwick has its own advantages, as it makes good use
of surface tension.

==============================================================================
TOPIC: JOBS&HOTPHOTOS
http://groups.google.com/group/sci.electronics.repair/t/f9c53727295e8f17?hl=en
==============================================================================

== 1 of 1 ==
Date: Tues, Jun 29 2010 8:34 am
From: srinivasulu ukkalam

FOR HEROIN HOT PHOTOS VISIT www.hotphotos.co.in

FOR JOBS http://jobsjackpot.blogspot.com/

hot lip kiss1
http://hotimagesandvideos.blogspot.com/2010/04/hot-lip-kiss1.html
hot hug
http://hotimagesandvideos.blogspot.com/2010/04/hot-hug.html
super hot kiss
http://hotimagesandvideos.blogspot.com/2010/04/super-hot-kiss.html
one lip kiss
http://hotimagesandvideos.blogspot.com/2010/04/one-lip-kiss.html
super navel kiss
http://hotimagesandvideos.blogspot.com/2010/04/super-navel-kiss.html
hot train lip kiss
http://hotimagesandvideos.blogspot.com/2010/04/hot-train-lip-kiss.html
hot boobs kiss
http://hotimagesandvideos.blogspot.com/2010/04/hot-boobs-kiss.html

==============================================================================
TOPIC: See Hot Sexy Star Aishwarya Nude Bathing Videos In All Angles.
http://groups.google.com/group/sci.electronics.repair/t/e6103e5e905a9b8e?hl=en
==============================================================================

== 1 of 1 ==
Date: Tues, Jun 29 2010 9:28 am
From: quick money

See Hot Sexy Star Aishwarya Nude Bathing Videos In All Angles.
at http://ukcitygirls.co.cc

Due to high sex content,i have hidden the videos in an image. in that
website on left side below search box click on image and watch
videos in all angles.please dont tell to anyone.

== 1 of 2 ==
Date: Tues, Jun 29 2010 10:03 am
From: "Arfa Daily"

I have a JVC hifi on my bench. Brand new, purchased by a British soldier
from a base somewhere else - possibly an American one, I seem to recall
being told. Oddly, for modern equipment, it has a voltage selector switch,
which was of course set to 120v, when he applied 240v UK power to it ...

The unit has a switch mode power supply (why though?) which is one of the
old style designs where the front end has two main filter caps, and the
input voltage is configured by how you jigger the connections of the reccy
and the caps. That is where the back panel voltage selector switch is
connected. Even more why though ? I would have thought that if you were
going to bother putting a switcher in a junky piece of hifi that was for
worldwide use, you would have used a design with an efficient PFC front end,
that makes it universal in terms of input voltage. Heaven knows, there's
enough cheap and cheerful examples out there, used by the million in LCD TV
sets.

Anyway, that aside, the bridge was twatted, as were two diodes?? , one
across each of the filter caps. These devices *look* like diodes, and the
symbol on the board is for a diode, and they're called D34 and D35, but I
can't recall having seen diodes in this position before. Voltage sharing
resistors, maybe. The type number on them is R4KL, and that's where the
problems start. All of the usual suspects - Datasheetarchive, Allicmall etc
deny knowing anything about this device. I can't seem to find any references
to the it on the net, other than lots of people on groups and forums, also
trying to find data. An admittedly brief trawl of some of those postings,
didn't seem to turn up any definitive answers. Some seem to be calling the
device a "transient suppressor" so maybe it's some kind of avalanche diode ?
Appears to be used in some monitors as well, so I'm surprised that it is so
difficult to turn up info.

Anyway, I've replaced the bridge, removed the short circuit
whatever-they-ares, and fired the supply up in isolation. It runs quite
happily without the "diodes" as you might imagine it would, and the output
voltages seem reasonable.

Apparently, the owner is being posted to Afghanistan or some such at the
weekend coming, and wants to take the hifi with him, so my back's against
the wall a bit on this one. In case of the remote possibility that anyone
has a service manual for the item, it's a JVC MX - KC68 or CA-MXKC68
depending on whether you have it listed by system or model number.

Any help then, please lads. TIA

Arfa

== 2 of 2 ==
Date: Tues, Jun 29 2010 10:50 am
From: "Vale"

"Arfa Daily" <arfa.daily@ntlworld.com> ha scritto nel messaggio
news:mHpWn.93263$tH4.24979@hurricane...
>I have a JVC hifi on my bench. Brand new, purchased by a British soldier
>from a base somewhere else - possibly an American one, I seem to recall
>being told. Oddly, for modern equipment, it has a voltage selector switch,
>which was of course set to 120v, when he applied 240v UK power to it ...

http://www.clubdediagramas.com/archivo/audio-equipos-de-musica-amplificadores-reproductores-etc-a7/jvc-m148/jvc-ca-mxkc68-manual-de-serviciopdf-f86697.html

Just register and download.
Spanish is not a problem, isn't it?

==============================================================================
TOPIC: Fire ants - computer bugs
http://groups.google.com/group/sci.electronics.repair/t/7eecdfe1b1971fbf?hl=en
==============================================================================

== 1 of 2 ==
Date: Tues, Jun 29 2010 10:56 am
From: JeffM

Jeff Liebermann wrote:
>carpenter ants[...]got into the TV antenna amplifier.
>Nothing was eaten, but they secreted some kind of acid,
>that ate the copper traces.
>
http://google.com/search?q=ants+formic-acid

Some birds have even figured out that squashed ants are useful.
http://google.com/search?q=ants+crows+formic-acid
There has been speculation that they get a buzz off this.

== 2 of 2 ==
Date: Tues, Jun 29 2010 11:28 am
From: Cydrome Leader

William R. Walsh <wm_walsh@hotmail.com> wrote:
> Hi!
>
>> Anyone have any operational experience of pc failure due to swarms
>> of fire ants ?
>
> Well, the circuit didn't fail and they weren't fire ants...but...
>
> I had a massive ants nest show up in an Optimus STA-795 stereo
> receiver. I noticed them moving around on the front panel, so I picked
> it up and WOW! Ants were pouring out of the bottom of the unit. The
> manual was underneath it, and they'd made some kind of a big white
> thing on top of it. I don't recall exactly what I did to evict them,
> but they never came back again.
>
> William

bugs seem to like heat, so things like vcrs were popular places for
roaches to live in.

you could tell from looking at a customer at the shop if you had to open
their electronics on newspapers and have a can of electronics cleaner
ready to kill anything that would run off.

==============================================================================

You received this message because you are subscribed to the Google Groups "sci.electronics.repair"
group.

To post to this group, visit http://groups.google.com/group/sci.electronics.repair?hl=en

To unsubscribe from this group, send email to sci.electronics.repair+unsubscribe@googlegroups.com

To change the way you get mail from this group, visit:
http://groups.google.com/group/sci.electronics.repair/subscribe?hl=en

To report abuse, send email explaining the problem to abuse@googlegroups.com

==============================================================================
Google Groups: http://groups.google.com/?hl=en

sci.electronics.repair - 19 new messages in 8 topics - digest

1:37 AM Penedão 0 comments

sci.electronics.repair
http://groups.google.com/group/sci.electronics.repair?hl=en

sci.electronics.repair@googlegroups.com

Today's topics:

== 1 of 1 ==
Date: Mon, Jun 28 2010 10:22 am
From: Phil Hobbs

On 6/27/2010 11:45 AM, Ron wrote:
> On 27/06/2010 16:36, Meat Plow wrote:
>> On Sun, 27 Jun 2010 07:59:49 +0100, N_Cook ǝʇoɹʍ:
>>
>>> Watched a nature TV prog on swarming behavior. Apparently these ants
>>> have stowed away on planes and taken up residence in airports in S USA
>>> states , infesting computers in air traffic systems etc. No mention in
>>> the program why jungle creatures have electric charge sensors in their
>>> antenna (stated in the narration) but they naturally home in on live
>>> circuit boards apparently and then swarm all over, causing mayhem.
>>> Anyone have any operational experience of pc failure due to swarms of
>>> fire ants ?
>>
>> I purchased an Anteater for insurance against a fire ant attack on my
>> electronics.
> you know what they say, aardvark never killed anybody

;)

Cheers

Phil Hobbs

(And it's illegal in some places: http://www.despair.com/effort.html )

--
Dr Philip C D Hobbs
Principal
ElectroOptical Innovations
55 Orchard Rd
Briarcliff Manor NY 10510
845-480-2058

email: hobbs at electrooptical dot net
http://electrooptical.net

==============================================================================
TOPIC: What on earth is a "Class 1 LED Product" ??
http://groups.google.com/group/sci.electronics.repair/t/c114dd1feeb17e72?hl=en
==============================================================================

== 1 of 8 ==
Date: Mon, Jun 28 2010 11:58 am
From: "Anon"

"Arfa Daily" <arfa.daily@ntlworld.com> wrote in message
news:GxZVn.97783$k15.95689@hurricane...
> Today, I had occasion to look at a set top box for cable TV service. It's
> a HDD recorder as well, employing what seems to be a standard computer
> disc drive. When I came to screw the lid back on, I noticed on the back
> panel, the words "Class 1 LED Product". What on earth do they mean by that
> ? I've seen similar statements for laser-based products such as CD players
> or DVD players / recorders, but in those cases, it is a warning. I'm not
> even sure that this unit has any LEDs in it, so in this case, does the
> word "LED" refer to something else ? What are Samsung (the makers of this
> box) trying to tell (warn??) us of here ... ?
>
> Arfa

The Classes assigned to laser products for eye safety are now being applied
to LEDs. I got a replacement 12V Outdoor Lighting Transformer that stated
it can not be used on Class II LED Products. That prompted me to look into
this issue recently. :)

Scott in Dunedin FL

== 2 of 8 ==
Date: Mon, Jun 28 2010 11:12 am
From: Meat Plow

On Mon, 28 Jun 2010 13:58:39 -0500, Anon ǝʇoɹʍ:

> "Arfa Daily" <arfa.daily@ntlworld.com> wrote in message
> news:GxZVn.97783$k15.95689@hurricane...
>> Today, I had occasion to look at a set top box for cable TV service.
>> It's a HDD recorder as well, employing what seems to be a standard
>> computer disc drive. When I came to screw the lid back on, I noticed on
>> the back panel, the words "Class 1 LED Product". What on earth do they
>> mean by that ? I've seen similar statements for laser-based products
>> such as CD players or DVD players / recorders, but in those cases, it
>> is a warning. I'm not even sure that this unit has any LEDs in it, so
>> in this case, does the word "LED" refer to something else ? What are
>> Samsung (the makers of this box) trying to tell (warn??) us of here ...
>> ?
>>
>> Arfa
>
> The Classes assigned to laser products for eye safety are now being
> applied to LEDs. I got a replacement 12V Outdoor Lighting Transformer
> that stated it can not be used on Class II LED Products. That prompted
> me to look into this issue recently. :)

That's pure madness!

== 3 of 8 ==
Date: Mon, Jun 28 2010 11:28 am
From: dplatt@radagast.org (Dave Platt)

In article <kO0Wn.56450$EK1.15950@newsfe15.ams2>,
Arfa Daily <arfa.daily@ntlworld.com> wrote:

>Well, yes, I suppose there is an *indicator* LED, but just the one, and it's
>hidden behind a coloured insert in the front panel, that surrounds a button
>assembly. I suppose if you are being really precise, there is a LED in the
>Toslink socket on the back as well, but then just about every piece of
>consumer electronics in existence now, has an indicator LED, and a Toslink
>socket or two on the back, and I've never seen any other item carry a
>similar statement about LEDs and classes. And to Mark, it's not a more
>accurate statement regarding a semiconductor laser in this case, because
>there's not one in it. No optical drive of any description. It's just a
>cable set top box with an HDD in it for recording.

Does it by any chance have a TOSLINK output, for providing digital-audio
signals to an A/V receiver/amplifier? A lot of STBs do, these days,
and this might require the Class 1 label.

== 4 of 8 ==
Date: Mon, Jun 28 2010 12:45 pm
From: AZ Nomad

On Mon, 28 Jun 2010 10:01:26 +0100, Arfa Daily <arfa.daily@ntlworld.com> wrote:
>Today, I had occasion to look at a set top box for cable TV service. It's a
>HDD recorder as well, employing what seems to be a standard computer disc
>drive. When I came to screw the lid back on, I noticed on the back panel,
>the words "Class 1 LED Product". What on earth do they mean by that ? I've
>seen similar statements for laser-based products such as CD players or DVD
>players / recorders, but in those cases, it is a warning. I'm not even sure
>that this unit has any LEDs in it, so in this case, does the word "LED"
>refer to something else ? What are Samsung (the makers of this box) trying
>to tell (warn??) us of here ... ?

Anybody know how to locate and power up a computer, open a web browser,
get to google.com and arrive at a clever search string like "Class 1 LED
Product"?

== 5 of 8 ==
Date: Mon, Jun 28 2010 1:48 pm
From: Adrian C

On 28/06/2010 20:45, AZ Nomad wrote:

> Anybody know how to locate and power up a computer, open a web browser,
> get to google.com and arrive at a clever search string like "Class 1 LED
> Product"?

No. Is that possible?

Do I need to wear any special protection while doing that?

--
Adrian C

== 6 of 8 ==
Date: Mon, Jun 28 2010 1:56 pm
From: AZ Nomad

On Mon, 28 Jun 2010 21:48:35 +0100, Adrian C <email@here.invalid> wrote:
>On 28/06/2010 20:45, AZ Nomad wrote:

>> Anybody know how to locate and power up a computer, open a web browser,
>> get to google.com and arrive at a clever search string like "Class 1 LED
>> Product"?

>No. Is that possible?

>Do I need to wear any special protection while doing that?

Doesn't microsoft have a warning "this browser is shit, using it may
destroy your computer and all the data that you hold dear, continue?"

== 7 of 8 ==
Date: Mon, Jun 28 2010 2:33 pm
From: Adrian C

On 28/06/2010 21:56, AZ Nomad wrote:
> On Mon, 28 Jun 2010 21:48:35 +0100, Adrian C<email@here.invalid> wrote:
>> On 28/06/2010 20:45, AZ Nomad wrote:
>
>>> Anybody know how to locate and power up a computer, open a web browser,
>>> get to google.com and arrive at a clever search string like "Class 1 LED
>>> Product"?
>
>> No. Is that possible?
>
>> Do I need to wear any special protection while doing that?
>
> Doesn't microsoft have a warning "this browser is shit, using it may
> destroy your computer and all the data that you hold dear, continue?"

'Yeah, but I find pressing the escape key cancels boring things that
might be confusing to me to read and it doesn't seem to do any harm ....'

(one of my users in care...)

--
Adrian C

== 8 of 8 ==
Date: Mon, Jun 28 2010 5:50 pm
From: David Nebenzahl

On 6/28/2010 2:33 PM Adrian C spake thus:

> On 28/06/2010 21:56, AZ Nomad wrote:
>
>> On Mon, 28 Jun 2010 21:48:35 +0100, Adrian C<email@here.invalid> wrote:
>>
>>> On 28/06/2010 20:45, AZ Nomad wrote:
>>>
>>>> Anybody know how to locate and power up a computer, open a web browser,
>>>> get to google.com and arrive at a clever search string like "Class 1 LED
>>>> Product"?
>>>
>>> No. Is that possible?
>>>
>>> Do I need to wear any special protection while doing that?
>>
>> Doesn't microsoft have a warning "this browser is shit, using it may
>> destroy your computer and all the data that you hold dear, continue?"
>
> 'Yeah, but I find pressing the escape key cancels boring things that
> might be confusing to me to read and it doesn't seem to do any harm ....'

Well, that's kinda true: pressing <ESC> at any prompt is kinda like
voting "no" on all ballot propositions (we get a lot of 'em here in
Kal-ee-fonia).

--
The fashion in killing has an insouciant, flirty style this spring,
with the flaunting of well-defined muscle, wrapped in flags.

- Comment from an article on Antiwar.com (http://antiwar.com)

==============================================================================
TOPIC: DATAMAN s4 eprom programmer , looking for GAL adaptor...
http://groups.google.com/group/sci.electronics.repair/t/2b308026e5f71b8d?hl=en
==============================================================================

== 1 of 1 ==
Date: Mon, Jun 28 2010 11:22 am
From: Scheini Karl

On 28 Jun., 14:40, "Jps" <formula1vhsNOS...@hotmail.com> wrote:

> i think i will cannot program any PAL / GAL chip...any idea?

How about GALBLAST?

See: http://www.armory.com/~rstevew/Public/Pgmrs/GAL/_ClikMe1st.htm

regards

Karl

== 1 of 2 ==
Date: Mon, Jun 28 2010 11:32 am
From: Geo

On Sat, 26 Jun 2010 19:57:31 -0500, "William R. Walsh"
<newsgroups1@idontwantjunqueemail.walshcomptech.com> wrote:

>I kept on looking and found a capacitor at location 7C27 (220uF, 16V) that
>had blown out the rubber plug at the bottom. So I replaced that. Now nothing
>works. I know the new cap to be good.

Is it a double-sided (or worse - multilayer) pcb?
If the pcb designer used one or both of the capacitor pins as vias then you
could possibly have removed sufficient of the hole plating to lose e.g a power
or ground through connection.

--
Geo

== 2 of 2 ==
Date: Mon, Jun 28 2010 5:12 pm
From: "Arfa Daily"

"William R. Walsh" <wm_walsh@hotmail.com> wrote in message
news:016c0e5e-f07c-4ecb-81be-4af0611b1632@r27g2000yqb.googlegroups.com...
> Hello all...
>
> Thanks to everyone for the replies...
>
> The new cap is installed properly. I made careful notes of how the old
> one had been installed and the schematic is in agreement with my
> notes.
>
> I do believe the "E0" indication is some kind of error. But what it
> means is a mystery, and the service manual does not help. I'm going to
> ask TEAC, although so far they have not been helpful at all. The
> output of the amplifier does not appear to be blocked--it is
> amplifying this humming sound. It's not outputting DC to the speaker
> connections.
>
> Outside of the burned area, no traces on the board were ruined.
>
> If I knew what E0 meant, I suppose it might be very helpful.
>
> I may try pulling the cap (since the original was completely open
> circuit, I doubt it can hurt) and seeing how the behavior changes.
>
> William

So what does the cap do in the circuit ? Is it a big secret, or something ?

Arfa

==============================================================================
TOPIC: Slightly OT - Apple OS4 on 2G Touch ...
http://groups.google.com/group/sci.electronics.repair/t/7e38c57ec16b1c11?hl=en
==============================================================================

== 1 of 2 ==
Date: Mon, Jun 28 2010 5:23 pm
From: "Arfa Daily"

"Jeff Liebermann" <jeffl@cruzio.com> wrote in message
news:j7ih26deuf9d1nup0lm7rq2s2ffc2smc5k@4ax.com...
> On Sun, 27 Jun 2010 09:36:01 -0700, Jeff Liebermann <jeffl@cruzio.com>
> wrote:
>
>>I ran a crude test last night. At midnight, my iPod Touch 2G showed
>>97% battery charge (using iSystemPro). 9 hrs later, it's at 89%.
>>Notification is set to check my stocks and eBay items every 15 minutes
>>via Wi-Fi.
>>
>>Here's another app to help run the battery down:
>><https://www.ihoundsoftware.com/ihound/template/iPhone.vm>
>>Much like LoJack for iPod Touch, iPad, etc. I just installed it.
>
> Argh. I installed iHound to send their server my location every 10
> minutes. The default was 3 minutes. I left iHound running overnight.
> The battery went from 97% to 32%. Ouch.
>
> I don't think it's Notifications that are sucking the battery power.
> Methinks the problem is leaving an application running that uses
> notifications or just CPU cycles when the iPod Touch is in standby. I
> usually display the desktop before turning off (actually standby)
> mine, so I haven't had much experience with what an application can do
> to the battery level if left running.
>
> --
> Jeff Liebermann jeffl@cruzio.com

No apps were running to the best of my knowledge, when the problem was
occurring. I installed an app that monitors the system processes, as well as
a lot of other things like the battery, and checked what the state of play
was before putting it to sleep. It showed the processor as being (typically)
96 - 97% idle. There was one app that *wanted* notifications access, but the
app was not running - or at least it wasn't running in the foreground.
Nothing had changed with this app or the way it was loaded, and it had not
caused a problem before. Maybe iOS 4 gives it what it wants in the
background. I guess this may be a bug, and because of that keeps the wifi
running pretty much continuously. I don't know where in the unit the wifi
module is located, but certainly, the back of the case was warm enough to
just about feel, up near the top. It never had been before, and isn't again
now.

I have actually deleted the app that wanted notifications access now, so it
might be an interesting experiment to turn notifications back on. I guess I
could also wave the unit at my spec anny, and see if there is any obvious
wifi activity from it, when it's asleep.

Arfa

== 2 of 2 ==
Date: Mon, Jun 28 2010 6:06 pm
From: Jeff Liebermann

On Tue, 29 Jun 2010 01:23:13 +0100, "Arfa Daily"
<arfa.daily@ntlworld.com> wrote:

>No apps were running to the best of my knowledge, when the problem was
>occurring.

So much for that theory.

>I installed an app that monitors the system processes, as well as
>a lot of other things like the battery, and checked what the state of play
>was before putting it to sleep. It showed the processor as being (typically)
>96 - 97% idle.

That's what you'll usually see. The iPod Touch does not support
(much) multitasking (thank you Apple) so the only application that's
really able to run has to be in the forground and running. An
application can be installed, but unless it has Steve Jobs personal
permission to run in the background, it's not going to burn any CPU
cycles.

>I don't know where in the unit the wifi
>module is located, but certainly, the back of the case was warm enough to
>just about feel, up near the top. It never had been before, and isn't again
>now.

Looking inside:
<http://www.ifixit.com/Teardown/iPod-Touch-2nd-Generation/586/1>
the wi-fi chip is near the top, next to the antenna:
<http://s1.guide-images.ifixit.net/igi/a11UeKjfQfuIIrHD.huge>
next to the gold test coax connector. Mouse over the Broadcom chip in
the right hand photo above the "Step 10" label.

>I have actually deleted the app that wanted notifications access now, so it
>might be an interesting experiment to turn notifications back on. I guess I
>could also wave the unit at my spec anny, and see if there is any obvious
>wifi activity from it, when it's asleep.

A passive Wi-Fi sniffer (Kismet) might show more. Spread Spectrum is
difficult to see on an SA. If Notification is on, you should see some
traffic when it wakes up. However, if you REALLY want to run the
battery down, turn off you wireless router at night. The iPod Touch
will try to find something with which to connect. Not finding any
open access points, it will go through the list of SSID's heard, thus
taking more time, and much more battery power.

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

== 1 of 3 ==
Date: Mon, Jun 28 2010 5:28 pm
From: "Arfa Daily"

"N_Cook" <diverse@tcp.co.uk> wrote in message
news:i0abre$2i3$1@news.eternal-september.org...
> Definitely PbF, resoldering the usual suspect points.
> I realised I was using the wrong gauge of cut down sewing needle and 2 of
> the preamp valve socket pins are highly suspect. Those glossy white
> ceramic
> mounts with holes just bigger than the valve pins.
>
>
If it continues to cut out, a generator, a 'scope and a meter should tell
all. Valve circuits are very simple and very straightforward to trace
signals in, and troubleshoot. Even if it is a bad PbF joint, it should be
easy enough to pin it down to at least a stage, and possibly to a specific
component, based on valve voltages.

Arfa

== 2 of 3 ==
Date: Mon, Jun 28 2010 6:03 pm
From: "Phil Allison"

"Arfa Daily"
>
> If it continues to cut out, a generator, a 'scope and a meter should tell
> all. Valve circuits are very simple and very straightforward to trace
> signals in, and troubleshoot.

** You don't service that many valve guitar amps - do you ??

The ones that were originally well made are now so old they have strange
faults most techs have never seen before - while the ones made more
recently have designed in faults never seen before by anyone.

A few examples.

1. Recent Marshall combo amps with fibreglass PCBs that become LEAKY when
hot - output valve bias goes crazy and even the phase splitter stage goes
way out of DC balance in normal operation because of leakage from anode
tracks to grid tracks. There is simply no fix for this problem.

2. Recent Gibson /Trace Elliot amps that develop mysterious crackling
noises all over the circuit due to the use of water soluble flux that was
never properly washed of the PCB. Removing the main PCB entirely and
washing it thoroughly in solvent is the only fix.

3. Same amps as above use 9 pin PCB mount sockets that SHRINK - yep,
the plastic material used to make the socket shrinks under the heat from
EL84s, reducing the pitch circle diameter so much it is impossible to fit a
new tube in the socket. Replacing all the output valve sockets is the only
fix.

Then there are all the issues with the valves themselves - all new
production now comes from China or the former USSR and most of the valves
have designed in faults of kinds that were never seen previously. Eg.
nearly all 12AX7s now crackle and pop if tapped with the back of a
screwdriver and/or have bad heater cathode hum or are very microphonic -
while octal power types often suffer from bad soldering (PbF ?) on the pins
causing all manner of weird intermittents when the solder joint lets go.

Yep - fixing valve amps is pure joy.

.... Phil

== 3 of 3 ==
Date: Tues, Jun 29 2010 12:17 am
From: "N_Cook"

Arfa Daily <arfa.daily@ntlworld.com> wrote in message
news:47bWn.34349$9c1.22170@hurricane...
>
>
> "N_Cook" <diverse@tcp.co.uk> wrote in message
> news:i0abre$2i3$1@news.eternal-september.org...
> > Definitely PbF, resoldering the usual suspect points.
> > I realised I was using the wrong gauge of cut down sewing needle and 2
of
> > the preamp valve socket pins are highly suspect. Those glossy white
> > ceramic
> > mounts with holes just bigger than the valve pins.
> >
> >
> If it continues to cut out, a generator, a 'scope and a meter should tell
> all. Valve circuits are very simple and very straightforward to trace
> signals in, and troubleshoot. Even if it is a bad PbF joint, it should be
> easy enough to pin it down to at least a stage, and possibly to a specific
> component, based on valve voltages.
>
> Arfa
>

Coincidence or action of high V on springiness of the socket metal?
One valve base, pin 1 , the other pin 6 , both anodes so killing throughput
if connection fails.

While on valve stuff , has anyone come across any output transformer or
mains transformer ,for that matter, in any equipment , where there is
failure of PbF joint inside the transformer where tail meets magnet wire?

==============================================================================
TOPIC: CLICK AND GET $1000 TO YOUR HOME.
http://groups.google.com/group/sci.electronics.repair/t/2033a5d56897d930?hl=en
==============================================================================

== 1 of 1 ==
Date: Mon, Jun 28 2010 9:55 pm
From: easy money

VISIT SITE http://ukcitygirls.co.cc AND

CLICK SEARCH BOX ABOVE BANNER

AFTER FILL YOUR NAME AND ADDRESS.

YOU CAN GET INSTANT $1000 TO YOUR HOME.

== 1 of 1 ==
Date: Tues, Jun 29 2010 12:40 am
From: "N_Cook"

8 pin SMD with blown hole in the casing. Top mark , very indistinct maybe 2
lines
0h963
0h37

==============================================================================

You received this message because you are subscribed to the Google Groups "sci.electronics.repair"
group.

To post to this group, visit http://groups.google.com/group/sci.electronics.repair?hl=en

To unsubscribe from this group, send email to sci.electronics.repair+unsubscribe@googlegroups.com

To change the way you get mail from this group, visit:
http://groups.google.com/group/sci.electronics.repair/subscribe?hl=en

To report abuse, send email explaining the problem to abuse@googlegroups.com

==============================================================================
Google Groups: http://groups.google.com/?hl=en

Electronics

sci.electronics.repair - 25 new messages in 7 topics - digest

sci.electronics.repair - 25 new messages in 11 topics - digest

sci.electronics.repair - 19 new messages in 8 topics - digest

Blog Roll

Blog Archive