Toshiba TV29C90 problem; Image fades to black...

[JW]

On Thu, 27 Jan 2005 19:51:50 -0500 "Art" <plotsligt@comcast.net> wrote in
Message id: <AOOdnSaCbY00EWTcRVn-hw@comcast.com>:

Really hard to debate with their "off shore" call and help centre.

Hey Art, I see you're posting through Comcast's news server. I was
wondering how you're managing that? I can't access the servers any more,
and got an email from Comcast saying they were shut down on Jan. first.

 

[marfalla]

Is there anyway to cross a number that doesn't show up on the 'normal'
cross reference sites like NTE. I have an old Wurlitzer jukebox and
need to replace a 'Texas Instrument# wt36d3' It also has '7322'
printed on it but I think thats a date code. It also has '140770'
printed on it. It has 3 pins, mounts to a heatsink and looks like a
7805 vr.

 

[Jason D.]

On Fri, 28 Jan 2005 13:26:02 GMT, "Shoreline Electronics"
<jstielau@snet.net> wrote:

Your flyback may have an open winding. I had this exact same chassis with
this problem.. Looky here!


If this doesn't do it , can you post a photo of the fault on the web
somewhere?

---------------------------------------------------------------
Text pasted from WinSTIPS 2.0
http://www.ServiceSoftware.com
---------------------------------------------------------------

TV trying to power up and get a POP! from the speaker is classic dud
flyback arcing inside causing tv to shut down with a POP. Get one
from RCA use your full service model # to get correct part. The
flyback location is T4401.

Sometimes this takes awhile and cost pretty penny too. Some of these
parts may be NLA due to this chassis age.

Watch out for those hot glue slathered all over the components!!! It
caused the solder joints to fail.

Cheers,

Wizard

 

[R]

Here are a couple of Yahoo groups that deal with Archos products. Maybe
someone there could offer a suggestion:
http://groups.yahoo.com/group/archos_hardware/
http://groups.yahoo.com/group/archosmultimedia/
http://groups.yahoo.com/group/ArchosGmini/

-Ron

"T i m" <news@spaced.me.uk> wrote:
Hi All,

I managed to repair my mates old mp3 player and bought it off him for
my daughter.

... SNIP ...
Any thoughts please folks?

All the best ..

T i m (in the UK)

 

[Jon Danniken]

"Tony Marsillo" wrote:

I agree with Lee, I have used http://www.news.individual.net/index.html
for
a few years and have found them to be very reliable. They do not carry any
alt. newsgroups.

That is blatantly incorrect. They most certainly *do* carry the alt.*
hierarchy, although as a text-only news server, they obviously do not carry
any alt.binaries.* groups.

In case you haven't heard, most groups in the alt.* hierarchy are *not*
binary groups. And stop top-posting you twit.

Jon

A: Because it fouls the order in which people normally read text.
Q: Why is top-posting such a bad thing?

A: Top-posting.
Q: What is the most annoying thing on usenet and in e-mail?

 

[mark]

If you want to get the convergence yoke out of the equation, just ring
it Bob Parker sells one for not to much.

"JURB6006" <jurb6006@aol.com> wrote in message
news:20050128220801.15036.00000203@mb-m21.aol.com...

Hi;

(I've tried to be thourough here)

As you know I've taken a new job. As such I am being "introduced" to all
the
dogs. Such fun.

Two Toshibas, one was a midaged one, H line or so, the other, today was a
D
line.

Both had the same initial symptom, blue horizontal covnergence was off,
and it
got worse when it warmed up, all of the sudden. Replacing the STKs
stabilized
it, but they both needed adjustment, and I don't mean just a little.
Controls
just barely had enough range. Now I really really hate to adjust a
problem, but
I did because we were under the gun, remember these are the dogs. I
checked all
the output circuitry and the problem must be in the digital board in the
newer
one, but what about the D line ?

Thing has pots, and the same waveforms are applied to the common pots for
each
function, thereafter it is buffed by an OP AMP.

Am I missing something here. Something different about the blue ?

You've seen the NAPs with the blue tube mounted closer to the mirror. I
assume
it's because of the difference in the wavelength of the light. I guess
this
allows them to use the same lens for all colors, but others do and they're
just
fine. I think I have seen some sets with different blue lens.

Can I conclude that blue convergence is pushed a bit harder in these sets
? Red
and blue convergence yokes are the same, and everything's the same in some
sets
and they seem to work just fine. Is it possible that the blue convergence
yoke
runs hotter making it more prone to a failure like partial pulverization
of the
core or something ? why else would it be able to be adjusted ? I checked
best I
can for a hard circuit fault and none seems to exist.

The only test I can figure out next is to tie the red H output to the
waveform
for the blue and compare the <u>voltage</u> waveforms. Actually even if I
was
aware of a tester that could ring a convergence yoke, it isn't worth it
for two
jobs. If any problems appear I'd rather test by substitution. Switch the
red
and blue and see if the problem folows.

See the thing is, every control has it's intended effect. There are no
clipping
artifacts on the screen. Supply is good, at least I think so, the +&amp;- 12s
are
11.57 and 11.something. The 5V is right on the money. Yoke return
resistors are
good.

The red was fine and geometry was good. The blue had a vertical line bow
that
opposed the side pincushion errors. There was also a horizontal linearity
error
in the direction of uncorrected convergence. Low gain would explain that,
but
not the bow. What it comes down to is if the impedance/inductance of the
winding in the blue convergence yoke is it, the STKs will put out less
voltage
at the same current.

Has anyone ever even seen a defective convergence yoke ? I haven't (well
maybe). Or, could this be one of those elusive STK eating problems ? This
set
has had the STKs changed before, but that doesn't prove much, except that
the
others who did it didn't do it well enough so you can't tell. (I don't
know
about anyone else but I consider that to be a standard for a totally
correct
job) Luckily the pads are fine.

I don't think it's a main yoke because the focus is good. Any ideas ? I
don't
just mean something helpful on this job, I mean what if this gives someone
an
idea to fix their nemesis ? That would be good.

I think a way to test these things is in order. Actually since it is a
current
source output stage, I think I/we can figure out a way to test it
definitively.
Perhaps by interrupting the signal connector and inputting our own test
waveform. It can probably be a square wave, and once we see a good one
this
would be a definitive test. If the output voltage is lower with the
standard
input, then the reactance of the yoke is low, with everything else being
equal.
Or a spectrum analyser, but that is out of reach for most shops for it's
(now)
limited purpose.

Even with a scope, there are other possibilities for such a device. The
only
problem is we need a standardized test signal that is effective, a picture
of
the waveform produced by a new (or good) part, and a square wave
generator.
Perhaps one resistor beyond that, so you know the source impedance.

A spectrum analyzer would give us the data to build a proper filter for
the
DUT, but really knowing the scope has greatly enrichened my experience in
this
field. I could simply compare that voltage waveform to that of the red.
Hmmmm,
check it out, I don't need ANYTHING from the manufacturer to do this. No
data
no nuthin.

I'm on the M___________ and unlike Pulp Fiction, I'm not sending the Wolf,
I am
the Wolf.

Well, thanks for being bored enough to read all this and thanks in advance
for
any ideas, not only about the Toshiba, but figuring out how to test
things. I'm
for anything that enhances the repair industry.

JURB

 

[T i m]

On Sat, 29 Jan 2005 02:56:16 GMT, "R" &lt;abuse@hotmail.com&gt; wrote:

Here are a couple of Yahoo groups that deal with Archos products. Maybe
someone there could offer a suggestion:
http://groups.yahoo.com/group/archos_hardware/
http://groups.yahoo.com/group/archosmultimedia/
http://groups.yahoo.com/group/ArchosGmini/

-Ron

Thanks for those Ron ..

All the best ..

T i m

 

[JayCee]

s0ny wrote:

do you got it ?
I want know why it display fail 023.

yes, i found the reason, the backup battery was dead
simply replace the battery, fixed

jef

 

[Ian French]

My father keeps mentioning a place called "Stuarts" in Reading, but as
yet i
haven't had the chance to look them up. Anyone know of them?


Hi Martin,

Just bought one of these myself, and will probably have a go at fixing
it myself. Firstly, I only have a manual for the D75, so if anyone can
help me with the D83 I would be grateful.

Lots of issues with mine, especially with the cracked and broken clear
selector on the timebase, so I will machine myself a new one out of
clear acrylic. As for the rest. When I've got mine working, I should be
an expert, so I will gladly have a look at yours for the cost of a few
beers!!!

Best regards

Jon

Hi Jon,

1) Its is "Stewarts" in Reading that you want.

2) I believe that the Telequipment D75 is a "Flat" version of the D83 and
the electronics inside is the same.

3) If you need a D75 for spares , cheap!, then email me.

Ian.

 

[terryyoung]

I have a Hitachi 43uwx10b 43 " TV, It has a convergence problem. I have
replaced both STK392-110's twice and this does not let me straighten the
red, blue,and green grid while doing the convergence adjustment. I have
been told that when these STK's go bad they take some resistors with them.
Can anyone tell me which resistors are possibly bad where they are on the
board and how I can tell if their shot? I would be forever in your debt if
I can get some help with this repair! Thanks, Terry

 

[NSM]

"Andrew Crawford" &lt;ve1vac-NOT@rac.ca-NOT&gt; wrote in message
news:bMXKd.221611$Np3.9274512@ursa-nb00s0.nbnet.nb.ca...

I have acquired a mid-90s JVC 20" TV. Quite a nice model, and I'd like
to set it up for the kids to watch their shows so I can occasionally use
the main TV to watch mine

Anyway, it's unwatchable due to a ghosting problem. This is something
I've usually associated with antennas, but there's no antenna in the set
up here.

* TV tuned to cable connection: strong ghost trailing by 1/8"
(note; any channel. Also other TV no ghost in same situation)

* TV on AV from a DVD player: strong ghost trailing by 1/8"

BUT

TV's own character generator in menus etc: beautiful, sharp edges with
no ghosting whatsoever.

Any ideas? I'm trying to figure out if this is work having repaired.

The video signal is being coupled into an input stage somewhere. Find
someone who has serviced this model before - they may be able to eyeball the
problem.
--
N

 

[Art]

Possible the mirror housing may be removed however the base cabinet still
may be too wide. Measure it to be sure.
&lt;khris.jose@gmail.com&gt; wrote in message
news:1107064482.441598.298390@z14g2000cwz.googlegroups.com...

Hello,

Having a little trouble getting our vs459 through a doorway. Is it
possible for the black back cover to be removed so the TV can be
positioned through a 26" doorway?

regards,

Khris

 

[Ohger1]

Subject: Re: Ford Radio Display Fix and Threats from a Phony Lawyer
From: "Sean Scott" Its@secret
Date: 1/10/05 10:19 AM Eastern


Speakig of which I just bought a Chevy Malibu and roadnoise is my ONLY
complaint, how did Ford solve this problem, would I be able to reduce
roadnoise in my car w/o lots of heavy insulation, I'd hate to lose a lot of
MPG because of insulation.

Ford particularly didn't solve the problem, but money will. I have a Ford
Windstar van that is very quiet, but it's nothing compared to a Mercedes or
BMW. You'll notice the bigger, more expensive Chevies are quieter compared to
the Malibu when you drive them. You can add (or add more) insulation between
the door frame and door panels, firewall insulation, and insulation below the
carpet, and this will quiet things considerably. This does add weight and cost
though.

 

[JURB6006]

Interesting. On this job one of the ICs did fail after replacement. The
original problem was the blue horiz channel, after running about ˝ an hour, the
grreen vert channel fried.

I did notice the the loop they bend into the pins was off. It wouldn't let the
IC seat completely so I rebent them. I mounted them and then pushed each one
with a screwdriver handle to relieve the stress.

Perhaps that's a sign that you got the crappy ones ? I'll see if they're still
around and get the lot number. Of course with AOL dropping newsgreoups I might
not be able to post it . . . .At least right away. We'll see.

JURB

 

It sounds to me like a bad delay line or an open termination to the
delay line, or possibly some other problem after the signal has been
demodulated down to the video level.

H. R. (Bob) Hofmann

 

[Andrew Crawford]

Thanks to all for replies - sounds like it might be worth taking for repair.

cheers,

Andrew

 

[kip]

Did you resolder that BIG blue box cap I thinks its a .99 or something like
that.

kip
"Shoreline Electronics" &lt;jstielau@snet.net&gt; wrote in message
news:K3rKd.24201$by5.22342@newssvr19.news.prodigy.com...

Your flyback may have an open winding. I had this exact same chassis with
this problem.. Looky here!


If this doesn't do it , can you post a photo of the fault on the web
somewhere?

---------------------------------------------------------------
Text pasted from WinSTIPS 2.0
http://www.ServiceSoftware.com
---------------------------------------------------------------

RCA CTC169EJ5

Raster Squashed Vertically. Has Osd But No Audio Or Video.

Jeff Stielau : 8/2/99 : Shoreline Electronics

Check -12v Supply Off Pin 7 Of Flyback. If It Measures +4vdc Or Something
Odd, Check For Open Pin 7 On Flyback

---------------------------------------------------------------



--
==========================
Jeff Stielau
Shoreline Electronics Repair
344 East Main Street
Clinton,CT 06413
860-399-1861
860-664-3535 (fax)
jstielau@snet.net
========================

"DHT112A" &lt;kenlg@mindspring.com&gt; wrote in message
news:1106508406.019494.248010@z14g2000cwz.googlegroups.com...
"I have a 35" Proscan 35123 direct view TV with a CTC169EJ5 board.
Manufactured in March of 96. I have replaced all the recommended parts
in the power supply and all voltages during idle and run are right on.
The original problem was a shorted HOT which was replaced along with
Q4302, Q2906, C4401, C4402 and C4403. I have had the flyback out and
it's resistances seem OK. A couple of times during the power supply
rebuild I put the board in the TV to put it in run and check some
voltages. When I turned it on it only had a bright narrow band across
the screen. Sound has always been fine. I tapped the flyback and it
came back to full screen. I have replaced Q4201 and Q4202 seems OK.

When the power supply rebuild was finished and I thought all was well
and we sat down to watch it, the thing suddenly popped through the
speakers and shut down. It does not try to restart but can be turned
back on by remote or power button on front panel only to pop and shut
down again. There is no certain time for shut down. It may be a
minute or two or just seconds. I see no burned, bulged or obviously
bad parts. The voltages don't appear to jump before shut down so I
don't think it is over voltage. The 143 volts at CR4116 drops then
comes back up in standby.

Now the picture has gone to a bright narrow band all the time with the
antenna hooked up and a dim thin rainbow colored football shape without
antenna. I have replaced U4501, CR4504, SCR501, Q4507, and Q4505. I
have checked the voltages in this area. All are good except pin 6 and 1
on U4501 are dead. All voltage around Q4801 are dead and there is no
voltage at the B and E on Q4803. The only thing I could find was a
cold solder joint where the yoke wire was hooked to the board causing a
resistance between the yoke connector and connection on the board. The
yoke resistance checks good.

The funny thing is it will stay on indefinitely while no antenna is
hooked to it but put the antenna on so it would have sound and picture
it pops and shuts down.

I plan on doing what I can but I have no scope. I have experience
building tube audio amps and understand tubes well but don't know much
about sand(transistors).
Any advice anyone can give will very much appreciated.

 

[JURB6006]

After all your work, if something really wierd happens, you'll pay.

If it works after the smoke comes out, you probably have a fried small disc
capacitor. Doesn't affect the tuning of the H sweep all that much, but fine
tunes it. Anything else burns it is either shorted or open. Of course this is
now open.

Is the geometry PERFECT ? I mean perfect.

JURB

 

[JURB6006]

Dude;

When you want to distribute a file like this, please put it in your webspace
and post a link. We seem to constantly have bandwidth etc. type problems. There
is too much traffic here.

Actually I'd like to see it, but I'll get it somewhere else.

I'm suprised binaries are even allowed here. They can put a total stop to it.
Videos are out of the question. I'm suprised it made it.

JURB

 

[Art]

Change Both and check the low value resistora in teh convergence output
circuit. Also check the convergence yokes, either by ringing or with an
accurate, low range, ohm meter.
"Arnold stewart" &lt;arnold.stewart@sympatico.ca&gt; wrote in message
news:W4eLd.1607$Ck1.289716@news20.bellglobal.com...

TV goes into shutdown. Removing the third convergence plug stops the TV
from going into shutdown. Re-plugging it causes the TV to function
normally, for a while. I can turn the TV on and off for a number of times,
then it goes back into shutdown.
It would appear that one STK 392-110 IC was changed. So I interchanged the
two ICs to see if the problem would move to another convergence plug. It
didn't. I'm thinking of changing one of these ICs.
Any opinions on this?