Toshiba TV29C90 problem; Image fades to black...

http://groups.yahoo.com/group/Bad-eBay-Sellers has links to several
complaint sites not all of which are eBay related.

N
 
The picture was pretty good. That's why it seems such a shame to junk the
set if it is something relatively easy to fix.

Thanks again!

Don



"Art" <plotsligt@comcast.net> wrote in message
news:go6dnZEWLLhJ5HXcRVn-tQ@comcast.com...
Actually using an ESR meter you will find a fairly large number of caps
that
may require replacing. The actual cost of those items are not all that
much.
How was the picture quality before the vertical finally failed, if it was
good, indicating the CRT is probably in fair shape, it may be worth while
attempting the repairs. May want to acquire a Sams Photofact for the set,
if
available, or a schematic, it will help you sort out what circuit you are
troubleshooting. Vertical Output should be a LA7837 or LA7838, a common
part. Also check for any supply resistors to the vertical circuit that may
have overheated or changed value.
"Don" <someone@somewhere.net> wrote in message
news:Tg_Fd.6633$KJ2.17@newsread3.news.atl.earthlink.net...
I actually asked about this set quite some time back, but unfortunately
have
lost me notes on the thread........

The set is a Mitsubishi CS-3515R (manufactured Oct 1992). When first
turned
on, the picture is collapsed into a horizontal line midway between the
top
and the bottom of the screen. Based on varying intensity and strong
green
from the menu items (e.g. channel, volume, etc), it seems the horizontal
scan is fine. Sometimes after 5-30 minutes (i.e. the set "warms up")
the
picture expands to full screen. Today when I was toying with it, the
picture would occasionally snap to full screen for less then a second
and
then collapse into the horizontal line.

Given this the above, I am guessing:

1) A case of dried electrolytics in the vertical section.

2) Bad IC in vertical section.


Now for the questions:

1) Is this "collapsed" picture a relatively common problem?

2) If it is, any estimate on cost to repair?

3) Is it user serviceable (i.e. replace caps C101, C02, etc)?

4) Given the set is in otherwise very good condition, is it worth
fixing?

Thanks!!

Don
Click to expand...
 
Phil,

Maybe a poor choice of words in using "toying". Didn't actually have the
set apart (or whacking it with a 2x4! More case of channel changing and
video source changing.

Between your response and Art's, I might take a peek inside. I'm more of a
digital type, but certainly know how to read a schematic, trace circuits,
and which end of the soldering iron to hold!

Thanks!


Don




"Phil Bowser" <pbowser@pa.net> wrote in message
news:Wg0Gd.150$4K3.35898@monger.newsread.com...
Given the fact that the set "sometimes" has a full picture, I believe
you need neither an IC or capacitors, although replacement of the
electrolytic capacitors around the vertical output would be good
preventive
maintenance.

Sounds to me like the solder connections have cracked around the pins
of
the vertical output IC (very common) and / or other components in that
area.
As you so adequately put "toying with it" - you probably momentarily
flexed
the circuit board or induced some physical impact that allowed the
connections to "make" and allow the set to develope a full picture for a
moment or so. If you're comfortable with a soldering iron, disconnect AC
power to it and have a good look at the pins of the IC with a magnifier,
and
resolder as needed.
Click to expand...
 
cvairwerks@tigerbyte.net wrote:
Wayne R. wrote:

TyWraps:

Cons:
Traditionalists don't like it
Shouldn't do it without the right tool
Wrong tension settings can damage jackets/guts
Cut ends on floor are slippery


You forgot a couple of biggies on the cons of TyWraps

1. They are not compatable with any fuels or lubricants or hydraulic
fluids.

2. They do not survive well in enviroments that are high vibration or
those that see very low temps or temps over 100F.
Click to expand...
Not to be argumentative, I think these are all good points, but these
first two are not completely true. Tiewraps work fine under the hood
of a car. They can survive a small amount of oil, and the temp is
often easily over 100F.

Of course they don't last forever. As per your third point, they'll
get brittle and fall apart eventually. You just replace them before
that happens.

3. They do not age well. They start getting brittle within a couple of
years unless they are in a stable office type enviroment.
Click to expand...
<rest snipped>

I think the two best tools you can use, to avoid making them too
tight, are your fingers and your brain :)
 
I just fixed one of these exact same models with the exact same problem Friday.
Problem was caused by loose solder connections on convergence IC's (STK392-110)
causing one of them them to overload and short; also cooked three output
resistors (1.5 ohm, 2.2 ohm, and 3.3 ohm 1 watt. Customer said TV had lost
convergence "several times" before going completely.
 
Just by the description, going by your not having problems with DVD input, I'd
say the problem is in the tuner, or one of the voltages going to it is
intermittant. If you have a VCR, you could use it for the tuner going in via
the video input. Free fix.
 
"Mac" <foo@bar.net> wrote in message
news:pan.2005.01.16.04.55.24.366737@bar.net...

| Maybe. But then the OP should have called it a "transformer" in the first
| paragraph, too.
|
| Because it was called a "charger" in the first paragraph and a
| "transformer" subsequently, I was genuinely confused and had to
| re-read the whole post.

It seemed clear it was a wall-wart. But if he runs it on 50 Hz at 120 VAC
it'll be toast.

N
 
"Jim Carriere" <jimcarriere@yahoo.nospam>

Not to be argumentative, I think these are all good points, but these
first two are not completely true. Tiewraps work fine under the hood
of a car. They can survive a small amount of oil, and the temp is
often easily over 100F.

Of course they don't last forever. As per your third point, they'll
get brittle and fall apart eventually. You just replace them before
that happens.

3. They do not age well. They start getting brittle within a couple of
years unless they are in a stable office type enviroment.

rest snipped

I think the two best tools you can use, to avoid making them too
tight, are your fingers and your brain :)
Click to expand...
Alas, someone with some common sense!

Tie wraps not only will handle a small amount of oil, but will handle lots
of oil and heat! DAMHIK! <g>

In *some* places, you can't beat am occasional tie wrap. You just gotta
have common sense!
--
Jim in NC
 
Doug Faunt N6TQS +1-510-655-8604 wrote:
Wayne R. <wruffner@KomKast.net> writes:


I do/have done a lot of both in telecom environments. Here's how I see
it:

Lacing:
Pros:
Looks good - only if you know what you're doing.
Keeps old farts happy
Cord is cheap
The few tools required are cheap & low tech
Cons:
Can look crappy after cable/hand 'abrasion'
Lots of labor
Learning curve can be long
Consistency of appearance is difficult,across crews especially
Can cut jackets/hands during installation
Gooey mess from excess wax
Cut ends on floor are sticky
QC inspections can be irrational



Since I find tie wraps user-unfriendly for cable that I actually have
to handle, but shrinking the whole thing together can be awkward, and
make for a very stiff assembly, I'm pleased to be reminded of cable
lacing.

I've laced several cable assemblies together now, using dental floss,
and that's accomplished exactly what I wanted.
Click to expand...
Isn't dental floss a little "sharp" (small diameter) for lacing? I'd be
afraid of it cutting into the wires over time.


Matt
 
Good suggestion, if the symptoms follow the VCR Tuner then you know it is
signal related (CATV Source). However if the VCR Tuner receives the material
and passes it into the TV via the Audio/Video inputs on the back of the set,
without the symptoms, then you can be assured you probably have a tuner
related problem in the TV.

"BWL" <btvfxer@aol.com> wrote in message
news:20050116011046.04400.00000053@mb-m12.aol.com...
Just by the description, going by your not having problems with DVD input,
I'd
say the problem is in the tuner, or one of the voltages going to it is
intermittant. If you have a VCR, you could use it for the tuner going in
via
the video input. Free fix.
Click to expand...
 
We've had quite enough of USA devices in Europe, particularly in Yugoslavia.
 
Some monitors use a small 8-pin IC to store
the settings into. It is a serial flash memory IC.
They have numbers like 24C04. They only cost
about $3 to $4 for the IC.
Some NECs use a 40-pin Weltrend IC that
contains RAM and static memory. It is a
specially programmed CPU that runs the
monitor. It is generally not available to purchase.
I would replace the 8-pin IC and hope that it
fixes the problem.
John
 
"Chris L." <chrisloll@gmail.com> wrote in message
news:1105862387.369452.254600@c13g2000cwb.googlegroups.com...
| Yesterday I went to turn my receiver on and listen to an album when I
....
| is still producing sound, but it sounds quite a bit like a blown
| speaker, with the static and rattling.

You need a scope and an audio oscillator, or a LOT of experience.

N
 
<andreas.manoli@gmail.com> wrote in message
news:1105866744.123630.220540@f14g2000cwb.googlegroups.com...

| From your postings I see that I should use a transformer of 240V->120V
| (and if the charger burns out in the future for whatever reason, then I
| will buy a variable transformer)

The problem is that the US transformer products have JUST enough iron for
120 VAC at 60 Hz. If you run them at 100 VAC on 50 Hz they will survive
(100/120 == 50/60). Used to do that in New Zealand and everything still ran
OK.

N
 
Reg Edwards wrote:
We've had quite enough of USA devices in Europe, particularly in Yugoslavia.
Click to expand...

I've had quite enough "double standards" regardless of country.

Some drive kilometers/hour, some pay in pesos, some drink fluid
ounces. Why is there a MMF but no milli-farad? How many yen is 10
euros? Why is spacecraft velocity measured in terrestral units/sec
instead of relative to C? A megohm is how many Mmho? How much does a
drop of liquid _____ weigh? A Siemen is what? How much does a 10-penny
nail cost? Will a euro device work in Pakistan? How tall is a horse?
How far is it to Alpha Centauri? How many cars still use a positive
chassis? How much energy does a hydrogen atom contain?

Oh dear, what was my name again?

It's not so much that it is too difficult to learn all these units
and standards, but the question is *why* all the units and standards?
Why must we devote so much cognitive effort to what amounts to
unneccesary and completely unproductive complexity? Is that going to
make us smarter? I'd wager that millions of hours of cognitive time is
wasted every day just in the confusion and adaptation of units and
measures. Why must we defend all these standards? Why must they
endure? Why not simplify the entire mess nad get everyone on the same
page? Why not *remove* some standards for a change, instead of
creating more new ones? At what point must something give? At what
point will the design break down? When is enough?

If the UK can systematically convert its entire economy over to a new
currency without so much as a hiccup, what does that say about our
capabilities?

I know, I know. Regarding scientists, the discoverers do deserve
credit for their discoveries. In elementary school we are taught
presidents and world history - but never who Ohm or Volta or Maxwell
is. This should be changed - it is important to know all the major
discoverers. So instead, we use their names in units of measurement.
Ohms and Volts and Maxwell's Equations. How flattering it must be, to
have your name used in daily conversation forever... and also how
egotistical. An airoplane isn't called a "DaVinci Flyer," even though
in many aspects he might have been the biggest initial conduit to
conceptualization. What's more, we're so accustomed to calling them
"planes" that "DaVinci Flyer" sounds downright absurd. Well most units
and measures sound like this literally. An ohm could be known as a
"hwernyoe" and as long as we learned it that way, that would sound
correct to us. Does "22 hwernyoe @ 12 yequilads = 0.545454 popuzingas"
make sense to you?

How about 12E / 22R = 0.545454I?

Defend it, if you must.

But if everyone used X EMF at X Frequency with X style plug, then
there'd be no bitching. Whose fault is that? Surely you don't say it's
all the US's fault. Is the logic "if all else fails, blame the US?" I
can't blame any country (even the US) for wanting to "retain their
individuality" but come on. Anyone who creates a double standard has
to live with the consequences. Nobody is forcing anyone to buy foreign
goods. I have to convert mL into quarts and pints all the time. But
wouldn't it be nice to have one set of standards?

Things would be very different, if I had a say in it. I suppose
you're glad I don't. Well at least we've got the free-speech thing
down, for the most part. Two billion more advancements to go.


-- "It's the new millennium. Do you know where your kids are?"
(Sponserd bt the fookt-on-honiks skool for newage edjumication) MCJ
20050116
 
Mark Jones wrote:
Reg Edwards wrote:

We've had quite enough of USA devices in Europe, particularly in Yugoslavia.




I've had quite enough "double standards" regardless of country.

Some drive kilometers/hour, some pay in pesos, some drink fluid
ounces. Why is there a MMF but no milli-farad? How many yen is 10
euros? Why is spacecraft velocity measured in terrestral units/sec
instead of relative to C? A megohm is how many Mmho? How much does a
drop of liquid _____ weigh? A Siemen is what? How much does a 10-penny
nail cost? Will a euro device work in Pakistan? How tall is a horse?
How far is it to Alpha Centauri? How many cars still use a positive
chassis? How much energy does a hydrogen atom contain?

Oh dear, what was my name again?

It's not so much that it is too difficult to learn all these units
and standards, but the question is *why* all the units and standards?
Why must we devote so much cognitive effort to what amounts to
unneccesary and completely unproductive complexity? Is that going to
make us smarter? I'd wager that millions of hours of cognitive time is
wasted every day just in the confusion and adaptation of units and
measures. Why must we defend all these standards? Why must they
endure? Why not simplify the entire mess nad get everyone on the same
page? Why not *remove* some standards for a change, instead of
creating more new ones? At what point must something give? At what
point will the design break down? When is enough?

If the UK can systematically convert its entire economy over to a new
currency without so much as a hiccup, what does that say about our
capabilities?

I know, I know. Regarding scientists, the discoverers do deserve
credit for their discoveries. In elementary school we are taught
presidents and world history - but never who Ohm or Volta or Maxwell
is. This should be changed - it is important to know all the major
discoverers. So instead, we use their names in units of measurement.
Ohms and Volts and Maxwell's Equations. How flattering it must be, to
have your name used in daily conversation forever... and also how
egotistical. An airoplane isn't called a "DaVinci Flyer," even though
in many aspects he might have been the biggest initial conduit to
conceptualization. What's more, we're so accustomed to calling them
"planes" that "DaVinci Flyer" sounds downright absurd. Well most units
and measures sound like this literally. An ohm could be known as a
"hwernyoe" and as long as we learned it that way, that would sound
correct to us. Does "22 hwernyoe @ 12 yequilads = 0.545454 popuzingas"
make sense to you?

How about 12E / 22R = 0.545454I?

Defend it, if you must.

But if everyone used X EMF at X Frequency with X style plug, then
there'd be no bitching. Whose fault is that? Surely you don't say it's
all the US's fault. Is the logic "if all else fails, blame the US?" I
can't blame any country (even the US) for wanting to "retain their
individuality" but come on. Anyone who creates a double standard has
to live with the consequences. Nobody is forcing anyone to buy foreign
goods. I have to convert mL into quarts and pints all the time. But
wouldn't it be nice to have one set of standards?

Things would be very different, if I had a say in it. I suppose
you're glad I don't. Well at least we've got the free-speech thing
down, for the most part. Two billion more advancements to go.


-- "It's the new millennium. Do you know where your kids are?"
(Sponserd bt the fookt-on-honiks skool for newage edjumication) MCJ
20050116
Click to expand...
Well said!


--
The e-mail address in our reply-to line is reversed in an attempt to
minimize spam. Our true address is of the form che...@prodigy.net.
 
"Mark Jones" <abuse@127.0.0.1> wrote in message
news:pIidnd2Ol9JAWnfcRVn-sg@buckeye-express.com...

| Things would be very different, if I had a say in it. I suppose
| you're glad I don't. Well at least we've got the free-speech thing
| down, for the most part. Two billion more advancements to go.

"People demand freedom of speech to make up for the freedom of thought which
they avoid".
Freedom of Speech - Kierkegaard, Soren - 1813-1855 Danish Philosopher Writer
 
Could be a driver IC, or maybe solder connections.

Mark Z.


"Chris L." <chrisloll@gmail.com> wrote in message
news:1105862387.369452.254600@c13g2000cwb.googlegroups.com...
Yesterday I went to turn my receiver on and listen to an album when I
noticed I was getting a lot of distortion in my right channel speaker.
I decided to test out what was going on. I moved the right speaker to
the B output on the right channel and was experiencing the same
static/distortion. I then switched the right speaker to the left A
output and everything worked fine. To be certain, I switched the left
speaker to the right channel to find the speaker was producing the same
sound as the right speaker had earlier. So anyway, it's certainly a
problem with the right channel and not the speakers. Both the A and B
outputs are producing this very distorted static sound. I don't have
much knowledge of audio electronics, but I have worked on electronics
before and can solder, etc. But when it gets down to it, I can't
imagine where to really begin. I imagine since the left channel is
working properly (and I'm assuming both match electronically) I could
easily see where the problem is, if I knew where to begin. I'm assuming
nothing blown, but could something need to be re-soldered? The channel
is still producing sound, but it sounds quite a bit like a blown
speaker, with the static and rattling.
Click to expand...
 
Found the problem
Upon disassembly, I found an area where there was a lot of overheating.
I found that 2 capacitors were badly overheated, C415 and C413 (101K,2KVA
rating ).
I changed them and the unit now had the high voltage startup but no more
flashing yellow which after downlaoding the Operating manual meant that was
a problem with it.


Hope this helps someone else with a similar problem.

"Aslaner" <Mikercana1@yahoo.ca> wrote in message
news:toiGd.41360$b64.1446987@news20.bellglobal.com...
I have this monitor, it must be a common problem.
It powers up, high voltage starts up, if I don't hook it up to a computer,
it shuts the high voltage and the front LED goes from green to amber
flashing. which is normal but when I hook up the cable it doesn't look
like it detects it?
The hight volatge does not start up again or the LED does not go green.
I suspect a component is faulty on the board at the neck of the picture
tube as the video cable goes there only.

Could it be that it has a video cable with different pinout (HD-15 type)
?
Click to expand...
 
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