Sony CRT TV. Audio OK. If the set is turned on all is normal for a minute
or so. Then the picture is gone and screen fills with uniform illumination
plus about 20 or so fine horizontal lines slightly tilted up on the right.
After a few more seconds the screen gradually gets very bright white and,
wham, the set clicks off by itself. If I turn the set on again it repeats.
Anyone have a clue as to what is wrong?

Alex

Model is ???

kip
"amcwill417" wrote in message
...
Sony CRT TV. Audio OK. If the set is turned on all is normal for a
minute
or so. Then the picture is gone and screen fills with uniform
illumination
plus about 20 or so fine horizontal lines slightly tilted up on the right.
After a few more seconds the screen gradually gets very bright white and,
wham, the set clicks off by itself. If I turn the set on again it
repeats.
Anyone have a clue as to what is wrong?

Alex

Model is Sony Triniton KV-32HSR10, purchased new 2 Dec 1991.

"kip" wrote in message
.. .
Model is ???

kip
"amcwill417" wrote in message
...
Sony CRT TV. Audio OK. If the set is turned on all is normal for a
minute
or so. Then the picture is gone and screen fills with uniform
illumination
plus about 20 or so fine horizontal lines slightly tilted up on the
right.
After a few more seconds the screen gradually gets very bright white
and,
wham, the set clicks off by itself. If I turn the set on again it
repeats.
Anyone have a clue as to what is wrong?

Alex

amcwill417 wrote:
Sony CRT TV. Audio OK. If the set is turned on all is normal for a minute
or so. Then the picture is gone and screen fills with uniform illumination
plus about 20 or so fine horizontal lines slightly tilted up on the right.
After a few more seconds the screen gradually gets very bright white and,
wham, the set clicks off by itself. If I turn the set on again it repeats.
Anyone have a clue as to what is wrong?

Alex




Sounds like a HV regulation problem, HV is increasing until the Xray
protection kicks it off. Could be as simple as a solder joint or a
capacitor.

amcwill417 wrote:
Sony CRT TV. Audio OK. If the set is turned on all is normal for a minute
or so. Then the picture is gone and screen fills with uniform illumination
plus about 20 or so fine horizontal lines slightly tilted up on the right.
After a few more seconds the screen gradually gets very bright white and,
wham, the set clicks off by itself. If I turn the set on again it repeats.
Anyone have a clue as to what is wrong?

look around the line transformer area for bad soldering, and change the
rgb filter capacitor (usualy rated 250 v 10uF or so, often on the crt
neckboard)
-B.

Read the original post, Gent stated "Indicating multiple horiz lines in
raster, [Retrace Lines], before going so bright that protection shutdown
occurs". Check the 200 Volt supply to the crt, each video output device,
etc. Sounds as if either the CRT may be bad, you have lost the 200 Volt
supply to the crt circuit, or one or more of the output devices have gone
bad. Since the raster is going "white" I'd presume probably loss of G2 or
the 200 Volt. Normally if one of the output devices were defective the
raster would indicate that particular colour before shutdown.
"b" wrote in message
ups.com...

amcwill417 wrote:
Sony CRT TV. Audio OK. If the set is turned on all is normal for a
minute
or so. Then the picture is gone and screen fills with uniform
illumination
plus about 20 or so fine horizontal lines slightly tilted up on the
right.
After a few more seconds the screen gradually gets very bright white and,
wham, the set clicks off by itself. If I turn the set on again it
repeats.
Anyone have a clue as to what is wrong?

look around the line transformer area for bad soldering, and change the
rgb filter capacitor (usualy rated 250 v 10uF or so, often on the crt
neckboard)
-B.

On Fri, 4 Nov 2005 19:28:27 -0600, "amcwill417"
wrote:

Sony CRT TV. Audio OK. If the set is turned on all is normal for a minute
or so. Then the picture is gone and screen fills with uniform illumination
plus about 20 or so fine horizontal lines slightly tilted up on the right.
After a few more seconds the screen gradually gets very bright white and,
wham, the set clicks off by itself. If I turn the set on again it repeats.
Anyone have a clue as to what is wrong?

Alex


Focus leaking to G2, overloading the horizontal section?

Tom

"amcwill417" wrote in message
...
Sony CRT TV. Audio OK. If the set is turned on all is normal for a
minute
or so. Then the picture is gone and screen fills with uniform
illumination
plus about 20 or so fine horizontal lines slightly tilted up on the right.
After a few more seconds the screen gradually gets very bright white and,
wham, the set clicks off by itself. If I turn the set on again it
repeats.
Anyone have a clue as to what is wrong?

Alex


11/5/2005
Thank you all for your replies which I will certainly take into
consideration when I attempt to do repairs. This will be the third time I
have had to repair this TV. The first time (about 10 years ago) the set
behaved erratically when subject to vibration. After much poking around
(with a long plastic rod) I found out that some components on the circuit
boards were loose. Amost all of the small voltage regulators (about half
the size of small postage stamps) were loose so I resoldered all I could
find and that fixed it. The second time I could not locate the problem but
resoldered all the solder joints (which looked very good) on the HV
transformer board and by pure luck that fixed it. This third time may be
more challenging! I will keep you informed but it will take some time -
maybe a few weeks because of other duties.

Alex

"amcwill417" wrote in message
...

"amcwill417" wrote in message
...
Sony CRT TV. Audio OK. If the set is turned on all is normal for a
minute
or so. Then the picture is gone and screen fills with uniform
illumination
plus about 20 or so fine horizontal lines slightly tilted up on the
right.
After a few more seconds the screen gradually gets very bright white
and,
wham, the set clicks off by itself. If I turn the set on again it
repeats.
Anyone have a clue as to what is wrong?

Alex


11/5/2005
Thank you all for your replies which I will certainly take into
consideration when I attempt to do repairs. This will be the third time I
have had to repair this TV. The first time (about 10 years ago) the set
behaved erratically when subject to vibration. After much poking around
(with a long plastic rod) I found out that some components on the circuit
boards were loose. Amost all of the small voltage regulators (about half
the size of small postage stamps) were loose so I resoldered all I could
find and that fixed it. The second time I could not locate the problem
but
resoldered all the solder joints (which looked very good) on the HV
transformer board and by pure luck that fixed it. This third time may be
more challenging! I will keep you informed but it will take some time -
maybe a few weeks because of other duties.

Alex

A HAPPY EVENT!
This Saturday evening I opened up the TV and removed one of the circuit
boards for inspection and resoldered some suspicious looking solder joints.
Then I replaced it and turned on the set and nothing changed - set still did
not work. Then I turned on the TV and pushed down on the HV transformer
with a long stick so as to distort the circuit board it is on and WHALA that
did the trick. The set now works fine!!! I guess I will have to resolder
components on this board sometime soon since I suppose there must be a loose
solder joint somewhere. I do not understand why this Sony TV has had so
many defective solder joints. It is a wonder that it has worked at all over
these many years.

Alex

"amcwill417" bravely wrote to "All" (05 Nov 05 22:59:36)
--- on the heady topic of " Problem for 15 year old 32" TV"

am From: "amcwill417"
am Xref: core-easynews sci.electronics.repair:347676

am A HAPPY EVENT!
am This Saturday evening I opened up the TV and removed one of the
am circuit boards for inspection and resoldered some suspicious looking
am solder joints. Then I replaced it and turned on the set and nothing
am changed - set still did not work. Then I turned on the TV and pushed
am down on the HV transformer with a long stick so as to distort the
am circuit board it is on and WHALA that did the trick. The set now works
am fine!!! I guess I will have to resolder components on this board
am sometime soon since I suppose there must be a loose solder joint
am somewhere. I do not understand why this Sony TV has had so many
am defective solder joints. It is a wonder that it has worked at all
am over these many years.


Alex,

Heat around power devices will cause thermal expansion and then
contraction when cooled. Eventually the solder becomes metal fatigued
and brittle. This increases resistivity of the solder and the joint
can even burn up in extreme cases.

Case in point, when replacing power transistors in audio amplifiers I
always used to leave a little semi-circular bend to the leads so that
as the devices heated up the bend would take up the slack and wouldn't
pull when cooled again.

A*s*i*m*o*v

.... Wasted power is current squared times the resistance.

"Asimov" wrote in message
...
"amcwill417" bravely wrote to "All" (05 Nov 05 22:59:36)
--- on the heady topic of " Problem for 15 year old 32" TV"

am From: "amcwill417"
am Xref: core-easynews sci.electronics.repair:347676

am A HAPPY EVENT!
am This Saturday evening I opened up the TV and removed one of the
am circuit boards for inspection and resoldered some suspicious looking
am solder joints. Then I replaced it and turned on the set and nothing
am changed - set still did not work. Then I turned on the TV and pushed
am down on the HV transformer with a long stick so as to distort the
am circuit board it is on and WHALA that did the trick. The set now
works
am fine!!! I guess I will have to resolder components on this board
am sometime soon since I suppose there must be a loose solder joint
am somewhere. I do not understand why this Sony TV has had so many
am defective solder joints. It is a wonder that it has worked at all
am over these many years.


Alex,

Heat around power devices will cause thermal expansion and then
contraction when cooled. Eventually the solder becomes metal fatigued
and brittle. This increases resistivity of the solder and the joint
can even burn up in extreme cases.

Case in point, when replacing power transistors in audio amplifiers I
always used to leave a little semi-circular bend to the leads so that
as the devices heated up the bend would take up the slack and wouldn't
pull when cooled again.

A*s*i*m*o*v

... Wasted power is current squared times the resistance.

A good practice. Based on my several experiences with this television may I
put forward a first rule for repair: First bang (somewhat gently)
everything you have access to - like kicking the tires of an older car. If
the trouble goes away even temporarily then suspect a loose connection
somewhere. For TVs or other devices with high voltages use a long insulated
rod, say a 3 foot long dry plastic rod, for safety.

Alex