Hi all,

I`ve got a Sony Trinitron Colour 4:3 PAL TV (KV-X2141D), purchased in
1993. It`s hooked up to cable TV. Lately I have been experiencing a very
odd problem, which I totally cannot explain. Perhaps someone here can help
me.

My display will all of a sudden `lose` the ability to show colour. The
image will only output black & white on every channel. The problem begins
after 30-60 minutes of use and therefore makes watching TV almost
impossible. Switching the TV off and back on again does not help. If I
wait an hour or so I get my colour back. But then my TV only takes minutes
to revert back into black & white. If I wait a day before turning it on
again the old pattern returns: black & white after 30-60 minutes of use.

Although my television is hooked up through a video with the cable signal,
I have confirmed that the problem is definitely my TV. When I use tv-out
on my computer (with a direct connection to the television) the same
problem occurs. That rules out both my video-recorder and my cable signal.
Which couldn`t have been the problem in the first place, as de signal
downstairs comes through in colour.

Here`s a twist: teletext always shows in colour, even when the tv signal
has dropped into black & white mode. I`m not an expert, but to me that
means that the screen itself is still working. I`m guessing something is
heating up and failing, but I can`t understand why the damage would not be
permanent or instantly occur.

Can anyone shed some light on this? Based on the symptoms, which is the
most likely place to look for the solution? Is it the TV or some cable or
something?

Any help appreciated.

Regards,
Willem van der Berg

Hi all,

I`ve got a Sony Trinitron Colour 4:3 PAL TV (KV-X2141D), purchased in
1993. It`s hooked up to cable TV. Lately I have been experiencing a very
odd problem, which I totally cannot explain. Perhaps someone here can help
me.

My display will all of a sudden `lose` the ability to show colour. The
image will only output black & white on every channel. The problem begins
after 30-60 minutes of use and therefore makes watching TV almost
impossible. Switching the TV off and back on again does not help. If I
wait an hour or so I get my colour back. But then my TV only takes minutes
to revert back into black & white. If I wait a day before turning it on
again the old pattern returns: black & white after 30-60 minutes of use.

Although my television is hooked up through a video with the cable signal,
I have confirmed that the problem is definitely my TV. When I use tv-out
on my computer (with a direct connection to the television) the same
problem occurs. That rules out both my video-recorder and my cable signal.
Which couldn`t have been the problem in the first place, as de signal
downstairs comes through in colour.

Here`s a twist: teletext always shows in colour, even when the tv signal
has dropped into black & white mode. I`m not an expert, but to me that
means that the screen itself is still working. I`m guessing something is
heating up and failing, but I can`t understand why the damage would not be
permanent or instantly occur.

Can anyone shed some light on this? Based on the symptoms, which is the
most likely place to look for the solution? Is it the TV or some cable or
something?

Any help appreciated.

Regards,
Willem van der Berg

The colour problem is a fault in the PAL decoder in the TV (you are in
Holland aren't you?)
Now its impossible to diagnose the problem from here, perhaps a faulty
crystal oscillator?
However I might be able to suggest a work-around.

Does your cable box have a menu option for RGB output?

And does that old Sony have a SCART socket?

If so, and the socket supports RGB input, you will get colour and a better
picture than before.

Teletext is an RGB signal routed internally, no surprise its unaffected.


--
Graham.

%Profound_observation%

On Fri, 22 Oct 2004 22:05:25 +0100, Graham wrote:

Hello Graham,

Thanks for your reply.

The colour problem is a fault in the PAL decoder in the TV (you are in
Holland aren't you?)

Yes I am.

Now its impossible to diagnose the problem from here, perhaps a faulty
crystal oscillator?
However I might be able to suggest a work-around.

Does your cable box have a menu option for RGB output?

And does that old Sony have a SCART socket?

If so, and the socket supports RGB input, you will get colour and a better
picture than before.

Teletext is an RGB signal routed internally, no surprise its unaffected.

Indeed, it`s hard to diagnose the problem without actually looking at the
unit. But from what you are saying I gather that the source of my problem
is a defect in the TV. In other words, something I cannot fix myself,
like replacing a cable or something. For now that is the most important
thing to know.

I am not entirely sure what you mean with a cable box, in Holland every
house simply has a coax connection. Hook your cable on and voila, there is
no box or any settings to change. Which means I am out of luck there I
guess...

It seems like I need to bring the unit in for repair, I am not sure I want
to do this. I mean, it`s an old TV and not the main one... the repair will
set me back at least 50 euros. I`m considering buying a TV card for my
computer as an intermediate solution and purchasing a widescreen LCD when
they become affordable.

BTW, tonight it worked for two hours. Yesterday it worked for 20 minutes.
Does that make any sense?

Regards,
Willem

There is a problem with the colour demodulator circuits. There are
probably come some components that have become thermo sensitive. This is
impossible to service over an email, but an experienced TV tech with the
proper setup can troubleshoot the demodulator, and locate the defective
component(s). This can be anything from a cap to the reference crystal.

--

Jerry G.
======

"Willem van der Berg" wrote in message
news Hi all,

I`ve got a Sony Trinitron Colour 4:3 PAL TV (KV-X2141D), purchased in
1993. It`s hooked up to cable TV. Lately I have been experiencing a very
odd problem, which I totally cannot explain. Perhaps someone here can
help
me.

My display will all of a sudden `lose` the ability to show colour. The
image will only output black & white on every channel. The problem
begins
after 30-60 minutes of use and therefore makes watching TV almost
impossible. Switching the TV off and back on again does not help. If I
wait an hour or so I get my colour back. But then my TV only takes
minutes
to revert back into black & white. If I wait a day before turning it on
again the old pattern returns: black & white after 30-60 minutes of use.

Although my television is hooked up through a video with the cable
signal,
I have confirmed that the problem is definitely my TV. When I use tv-out
on my computer (with a direct connection to the television) the same
problem occurs. That rules out both my video-recorder and my cable
signal.
Which couldn`t have been the problem in the first place, as de signal
downstairs comes through in colour.

Here`s a twist: teletext always shows in colour, even when the tv signal
has dropped into black & white mode. I`m not an expert, but to me that
means that the screen itself is still working. I`m guessing something is
heating up and failing, but I can`t understand why the damage would not
be
permanent or instantly occur.

Can anyone shed some light on this? Based on the symptoms, which is the
most likely place to look for the solution? Is it the TV or some cable
or
something?

Any help appreciated.

Regards,
Willem van der Berg

On Fri, 22 Oct 2004 23:54:04 +0200 Willem van der Berg
wrote:

BTW, tonight it worked for two hours. Yesterday it worked for 20 minutes.
Does that make any sense?

Was it cooler last night than it was the night before? Your problem
sounds temperature related, so if the set starts out cooler, then it
will take it longer to warm up to the failure temp.

-
-----------------------------------------------
Jim Adney
Madison, WI 53711 USA
-----------------------------------------------

On Sat, 23 Oct 2004 20:10:04 -0500, Jim Adney
wrote:

On Fri, 22 Oct 2004 23:54:04 +0200 Willem van der Berg
wrote:

BTW, tonight it worked for two hours. Yesterday it worked for 20 minutes.
Does that make any sense?

Was it cooler last night than it was the night before? Your problem
sounds temperature related, so if the set starts out cooler, then it
will take it longer to warm up to the failure temp.

-
-----------------------------------------------
Jim Adney
Madison, WI 53711 USA
-----------------------------------------------

Bad solder connection on the colour oscillator?

Tom

Willem van der Berg wrote in
news
Hi all,

I`ve got a Sony Trinitron Colour 4:3 PAL TV (KV-X2141D), purchased in
1993. It`s hooked up to cable TV. Lately I have been experiencing a
very odd problem, which I totally cannot explain. Perhaps someone here
can help me.

My display will all of a sudden `lose` the ability to show colour. The
image will only output black & white on every channel. The problem
begins after 30-60 minutes of use and therefore makes watching TV
almost impossible. Switching the TV off and back on again does not
help. If I wait an hour or so I get my colour back. But then my TV
only takes minutes to revert back into black & white. If I wait a day
before turning it on again the old pattern returns: black & white
after 30-60 minutes of use.

Although my television is hooked up through a video with the cable
signal, I have confirmed that the problem is definitely my TV. When I
use tv-out on my computer (with a direct connection to the television)
the same problem occurs. That rules out both my video-recorder and my
cable signal. Which couldn`t have been the problem in the first place,
as de signal downstairs comes through in colour.

Here`s a twist: teletext always shows in colour, even when the tv
signal has dropped into black & white mode. I`m not an expert, but to
me that means that the screen itself is still working. I`m guessing
something is heating up and failing, but I can`t understand why the
damage would not be permanent or instantly occur.

Can anyone shed some light on this? Based on the symptoms, which is
the most likely place to look for the solution? Is it the TV or some
cable or something?

Any help appreciated.

Regards,
Willem van der Berg

Common faults that cause this problem in this vintage of Sony european sets
are dry joints on and in the tuner/IF can, plus an intermittent trimmer
CT202 ?