Widescreen Blue Blooming TV ! 1yr later goes flashes Green and shuts down ...nice

[JM]

Hi

TV has started flashing green and shutting down. Did this once a
month or so now every few hours. Sometimes, TV steadies after green flash
and recovers only to shut down later. Suggestions for a fix include:

1. Intermittent H-K carbon particle short - 1kV - 2amp diode on CRT
board may fix gun short

2. Common particle green cathode to heater short ?

Any ideas or advice appreciated

Thanks

JM

PS Details of previous problem with same set a year inlcudes that
ended in a CRT replacement.






JVC AV-32WP2EK 32"
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From: JM - view profile
Date: Thurs, Feb 17 2005 2:44 pm
Email: "JM" <[email protected]>
Groups: sci.electronics.repair
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Hi

I have the above model 32" widescreen TV that intially starts up OK
for
first 30secs but then blooms into blue with thin horozontal sloped
lines in
blue.
Blueness gradually fades over the next 10-20minutes to a perfect
picture
which lasts without further problem. Checking the web a positor
preventing
degaussing appears a possibility. Though switching on/off doesn't
help much
and no speakers are near by and TV has been unplugged and started
repeatly.


Any other suggestions / theories ? Can using service mode help
further ?


Thanks


JM






From: b - view profile
Date: Fri, Feb 18 2005 1:10 am
Email: [email protected] (b)
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- Hide quoted text -
- Show quoted text -

Hi

I have the above model 32" widescreen TV that intially starts up OK for
first 30secs but then blooms into blue with thin horozontal sloped lines in
blue.
Blueness gradually fades over the next 10-20minutes to a perfect picture
which lasts without further problem. Checking the web a positor preventing
degaussing appears a possibility. Though switching on/off doesn't help much
and no speakers are near by and TV has been unplugged and started repeatly.


Any other suggestions / theories ? Can using service mode help

further ?

Thanks

JM

Are you talking about retrace lines?
this is almost certainly not a degauss problem.
dont touch the service mode, this sounds like component failure.
check: components on crt neck board, video drivers, possibly crt
socket?

-
B


Rate this post: Text for clearing space





From: Phil Bowser - view profile
Date: Fri, Feb 18 2005 5:35 am
Email: "Phil Bowser" <[email protected]>
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I agree with "b" - it certainly does not sound degaussing related,
based
on your description of the problem.

The only thing that "puzzles" me about the situation is your
description
of "gradually" returning to normal. In the event of either solder
connections, or a H-K short I would expect the screen to abruptly
change
from normal to blue (or green) (or red), but not gradually... If it
were in
front of me, I would be using the old beat-on-it routine to try and
decide
if you're dealing with solder connections or a tube. If minor bumps
to the
cabinet or movement of the set corrects it, it is probably solder
connections. If it requires a really hard slap to the face of the
tube with
the palm of your hand, I would say you've got an intermittent H-K
short in
the CRT (Picture tube). If it doesn't respond at all to this
tormenting,
you're probably looking at some solid state failure / electrically
leaky
component like a video drive transistor, or AKB feedback component
(You'll
need a schematic & parts list.)


Due to the fact that the symptom CHANGES, - leave the service
menus
ALONE! - You'll only create for yourself another problem you'll have
to go
back and correct once you fix the real problem.







- Hide quoted text -
- Show quoted text -

Hi

I have the above model 32" widescreen TV that intially starts up OK for
first 30secs but then blooms into blue with thin horozontal sloped lines
in
blue.
Blueness gradually fades over the next 10-20minutes to a perfect picture
which lasts without further problem. Checking the web a positor preventing
degaussing appears a possibility. Though switching on/off doesn't help
much
and no speakers are near by and TV has been unplugged and started repeatly.


Any other suggestions / theories ? Can using service mode help

further ?

Thanks

JM

Rate this post: Text for clearing space





From: JM - view profile
Date: Fri, Feb 18 2005 11:32 am
Email: "JM" <[email protected]>
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Phil

Phil


I like your style...slap the TV about a bit, make it talk Jack Bauer
style.
Few more details:


Picture always starts good 30sec-1mins ish. Blueness appears and
intensifies until picture is bleached out completely but then
gradually the
picture reappears and the blueness fades. Sometimes the blueness fades
quickly <5mins, picture can then flicks from perfect to over colored
(usually yellowy) I mean deeper tonal/contrast for a split second then
flicks back less than a second to normal. TV has then run for 5mins
but
then apparently shorts out and shuts down - but its only done this 2/3
times. Usually, the picture stabilises and set will run fine for hrs
on
end. However, restarting the TV when warm doesn't prevent problem,
just
starts over again, stabilises and then OK.


A TV tech friend is coming round Sat, he thought "CRT short" but
expected
set to short out everytime after a few minutes.
I'll give it a good seeing to tonight .and see what happens.


Thanks


JM







- Hide quoted text -
- Show quoted text -

I agree with "b" - it certainly does not sound degaussing related,
based
on your description of the problem.

The only thing that "puzzles" me about the situation is your
description
of "gradually" returning to normal. In the event of either solder
connections, or a H-K short I would expect the screen to abruptly change
from normal to blue (or green) (or red), but not gradually... If it were
in
front of me, I would be using the old beat-on-it routine to try and decide
if you're dealing with solder connections or a tube. If minor bumps to
the
cabinet or movement of the set corrects it, it is probably solder
connections. If it requires a really hard slap to the face of the tube
with
the palm of your hand, I would say you've got an intermittent H-K short in
the CRT (Picture tube). If it doesn't respond at all to this tormenting,
you're probably looking at some solid state failure / electrically leaky
component like a video drive transistor, or AKB feedback component (You'll
need a schematic & parts list.)

Due to the fact that the symptom CHANGES, - leave the service menus
ALONE! - You'll only create for yourself another problem you'll have to go
back and correct once you fix the real problem.


lines help

further ?








From: JVC Dude - view profile
Date: Fri, Feb 18 2005 8:10 pm
Email: "JVC Dude" <[email protected]>
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Certainly sounds like the tube to me...
The Philips 32" tubes used in these sets have been much more
reliable
than the 28" wide and 29" 4:3 ones from the late 90s, but the
change of
colour cast is a similar tell tale sign...

gentle!! tapping on the tube neck might cause flashes or casts to
change,
confirming the diagnosis. Sometimes you can clean them up with a tube
rejuvenator but these tubes have a very low heater tolerance to the
increased voltage used in the boost/clean process- The heater for one
colour
can easily fail !!


AW







- Hide quoted text -
- Show quoted text -

Phil


I like your style...slap the TV about a bit, make it talk Jack Bauer
style.
Few more details:

Picture always starts good 30sec-1mins ish. Blueness appears and
intensifies until picture is bleached out completely but then gradually
the
picture reappears and the blueness fades. Sometimes the blueness fades
quickly <5mins, picture can then flicks from perfect to over colored
(usually yellowy) I mean deeper tonal/contrast for a split second then
flicks back less than a second to normal. TV has then run for 5mins but
then apparently shorts out and shuts down - but its only done this 2/3
times. Usually, the picture stabilises and set will run fine for hrs on
end. However, restarting the TV when warm doesn't prevent problem, just
starts over again, stabilises and then OK.

A TV tech friend is coming round Sat, he thought "CRT short" but expected
set to short out everytime after a few minutes.
I'll give it a good seeing to tonight .and see what happens.






it
were and
decide short
in

have to
go

sloped
lines

further
?

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From: John Mercer - view profile
Date: Sun, Feb 20 2005 4:42 pm
Email: "John Mercer" <[email protected]>
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Confirmed as tube......replacement with a 2yr one is going to be
£100inc P&L
so probably try that!

Thanks


JM