Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems.

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Default Color bleeding on 19" Toshiba TV

I have a transistorized Toshiba 19" color TV that I purchased in 1984.
It has worked quite well over the years, but recently has been
exhibiting a symptom which I would describe as a horizontal "bleeding"
of color under certain conditions.

Specifically, bright images on the screen (such as white shirts,
brightly-lit windows, white lettering, etc.) will exhibit a bluish
bleeding or tearing effect, always horizontally to the right of the
bright object. The picture is otherwise very good and stable, with
good contrast, color, and brightness.

Is this likely to be cause by some kind of adjustment out of whack?
Components (maybe condensers?) going bad? As mentioned, this is a
transistor set so I know it's not a weak tube causing the problem.
Thanks for any help with this!
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Default Color bleeding on 19" Toshiba TV


"pdp11tech" wrote in message
...
I have a transistorized Toshiba 19" color TV that I purchased in 1984.
It has worked quite well over the years, but recently has been
exhibiting a symptom which I would describe as a horizontal "bleeding"
of color under certain conditions.

Specifically, bright images on the screen (such as white shirts,
brightly-lit windows, white lettering, etc.) will exhibit a bluish
bleeding or tearing effect, always horizontally to the right of the
bright object. The picture is otherwise very good and stable, with
good contrast, color, and brightness.

Is this likely to be cause by some kind of adjustment out of whack?
Components (maybe condensers?) going bad? As mentioned, this is a
transistor set so I know it's not a weak tube causing the problem.
Thanks for any help with this!


picture tube (CRT) showing signs of age, IMO.
Time for a new TV. After 23 years, I believe you've got your money out of
the Toshiba.


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Default Color bleeding on 19" Toshiba TV

On Dec 7, 12:29 am, "Deke" no wrote:
picture tube (CRT) showing signs of age, IMO.
Time for a new TV. After 23 years, I believe you've got your money out of
the Toshiba.


Actually I don't really think of the Toshiba as all that old, it's my
newest set and I have older ones (vacuum-tube type) that are still in
regular use.

I don't care much for those strange new futuristic flat sets, and the
Toshiba fits perfectly in my home entertainment center -- guess I'll
have to keep an eye out for a good used TV that's similar.

Thanks for your input...
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Default Color bleeding on 19" Toshiba TV

Try replacing the electrolytic caps on the video driver board. It doesn't
cost much and it's not difficult.




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Default Color bleeding on 19" Toshiba TV

On Dec 7, 8:17 am, "William Sommerwerck"
wrote:
Try replacing the electrolytic caps on the video driver board. It doesn't
cost much and it's not difficult.


Actually this set has just a single circuit board in the bottom of the
chassis. (I've gone into it before to tweak the vertical height which
started shrinking a bit a few years ago.) Replacing the electrolytics
is probably not a bad idea, though, they're pretty likely to be drying
out at this point and starting to cause problems.
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Default Color bleeding on 19" Toshiba TV

Deke no wrote:

: "pdp11tech" wrote in message
:
: Specifically, bright images on the screen (such as white shirts,
: brightly-lit windows, white lettering, etc.) will exhibit a bluish
: bleeding or tearing effect, always horizontally to the right of the
: bright object. The picture is otherwise very good and stable, with
: good contrast, color, and brightness.

: picture tube (CRT) showing signs of age, IMO.
: Time for a new TV. After 23 years, I believe you've got your money out of
: the Toshiba.


No, as someone else mentioned, it's time to start pulling electrolytics. I'd
bet the CRT is fine.

The description of the problem I remember quite well, flaring, comet tails,
color bleeding off one edge, always going in the same direction. Don't
remember working on Toshiba's but remember the problem was common on
Panasonics and Quasars in that period (early/mid 80's).

They were probably the 1st generation that used video jungles, complex large
scale ic's to near do everything from take in from the tuner and spit out
RGB.

I'd try to narrow down odd ball caps around anything that looks like the
video processor ic, 1uf at 160v or 200uf at 3v, anything that is marked that
seems lop-sided with rating vs. voltage or visa versa.

I remember it was harder to find (at that time) the replacements over which
one was bad.

Just saying it's more likely a problem in the video stage rather than power
supply, horizontal/high voltage sections or CRT and related convergence
controls.

But I do agree, with it at the quarter-century mark at age, I wouldn't put
that much effort in it, rainy day project at best.

-bruce

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Default Color bleeding on 19" Toshiba TV


"Deke" no wrote in message
...

"pdp11tech" wrote in message
...
I have a transistorized Toshiba 19" color TV that I purchased in 1984.
It has worked quite well over the years, but recently has been
exhibiting a symptom which I would describe as a horizontal "bleeding"
of color under certain conditions.

Specifically, bright images on the screen (such as white shirts,
brightly-lit windows, white lettering, etc.) will exhibit a bluish
bleeding or tearing effect, always horizontally to the right of the
bright object. The picture is otherwise very good and stable, with
good contrast, color, and brightness.

Is this likely to be cause by some kind of adjustment out of whack?
Components (maybe condensers?) going bad? As mentioned, this is a
transistor set so I know it's not a weak tube causing the problem.
Thanks for any help with this!


picture tube (CRT) showing signs of age, IMO.
Time for a new TV. After 23 years, I believe you've got your money out of
the Toshiba.


If the picture tube is still bright, and has good color balance, i.e. no
missing single red, green, or blue, the tube is likely fine. The age of the
TV really doesn't mean anything with regards to tube life if the set has had
infrequent use.

If you've got a few hours, I'd replace all of the electrolytics. It'll
likely cost you less than $20 in parts. If you'd rather a newer set, you
can pick up a new-ish CRT set for practically nothing these days at any pawn
shop or secondhand store. I was at the dump the other day and they had
hundreds of new-looking sets on pallets, shrink-wrapped slated to go to some
recycling facility... people actually throw out perfectly good televisions
because they want a flat-screen. The current TV in my livingroom, a 27"
Toshiba, was put out by the curb on garbage day. I picked it up, replaced a
$5 regulator and a handful of caps and it's been working perfectly ever
since.

You say you do not like "those strange new futuristic flat sets". To each
their own, but if you give them a look I think you'll find the picture
quality is better than most CRT's. They also use less electricity and take
up much less space. Probably generate less heat too. Unfortunately,
they're not particularly user-serviceable.

Your statement harkens up memories of 'me old grandpappy and his dislike of
"them newfangled iron horses and moving pictures." I don't mind certain
aspects of technology, but still enjoy the glow from my tube amplifier in a
darkened room.

Dave S.


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Default Color bleeding on 19" Toshiba TV

On Dec 7, 10:41 am, Bruce Esquibel wrote:

The description of the problem I remember quite well, flaring, comet tails,
color bleeding off one edge, always going in the same direction. Don't
remember working on Toshiba's but remember the problem was common on
Panasonics and Quasars in that period (early/mid 80's).


That's the problem exactly.

They were probably the 1st generation that used video jungles, complex large
scale ic's to near do everything from take in from the tuner and spit out
RGB.


Same with this set, it has a single circuit board in the bottom with
what I would consider to be an amazingly small number of components
for a color television.

I'd try to narrow down odd ball caps around anything that looks like the
video processor ic, 1uf at 160v or 200uf at 3v, anything that is marked that
seems lop-sided with rating vs. voltage or visa versa.


Sounds like a plan, or maybe I should just recap the whole set,
probably wouldn't be much money and just an afternoon's work with a
soldering iron. Will have to pull the back off and take inventory of
the electrolytics.

But I do agree, with it at the quarter-century mark at age, I wouldn't put
that much effort in it, rainy day project at best.


It will be less work than trying to revamp my entire home
entertainment unit for a TV with a different form factor. :-) Also I
hate the idea of discarding something that probably just needs minor
repairs. I am still seeing new CRT-type sets around for sale that
would fit, but they look like cheap Chinese junk that would probably
last about six months and would be pretty much unrepairable.
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Default Color bleeding on 19" Toshiba TV

On Dec 7, 2:18 pm, "Dave" wrote:

Your statement harkens up memories of 'me old grandpappy and his dislike of
"them newfangled iron horses and moving pictures." I don't mind certain
aspects of technology, but still enjoy the glow from my tube amplifier in a
darkened room.


I just like to stick with what I'm familiar with and works well.
(Since you mention it, I have vacuum-tube equipment as well that I
still use and keep in repair.)

Thanks everyone for the suggestions, I'll have to take a look at
replacing some or all of the elecrolytics in this puppy...


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Default Color bleeding on 19" Toshiba TV

Dave wrote:
You say you do not like "those strange new futuristic flat sets". To each
their own, but if you give them a look I think you'll find the picture
quality is better than most CRT's.


Depends. Given a good video source, I agree. But HDTV is so full of nasty
digitization artifacts that I would rather watch an NTSC signal from 100
miles away with rabbit ears. I am not exaggerating.

--
Dec. 6 (Bloomberg) -- Government officials and activists flying to Bali,
Indonesia, for the United Nations meeting on climate change will cause
as much pollution as 20,000 cars in a year.
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