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Mark Zacharias Mark Zacharias is offline
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Default TV sound volume decreases as picture gets dark

"Joe" wrote in message
.. .
In article , N_Cook
wrote:

On 09/04/2014 20:51, Joe wrote:
I have a 10 year old Apex TV, (CRT picture tube).

It has gradually acquired some irritating faults, but now has one that
is pretty much intolerable.

When the picture (i.e., the scene) gets dim or very dark, the audio
level drops, practically to inaudibility.

I presently have more time than money, and I think I would like to
repair this TV if it's possible.

Could this audio symptom be the result of failing capacitors? If so,
approximately how many capacitors might be involved, and what is a
guesstimate for the cost of these capacitors?

If the symptom is almost certainly due to some other cause, what might
it be?

Oh, the reason I would like to attempt the repair is that the picture
is
still sharp, bright and contrasty.

Thanks.

--- Joe


Is it the same fault if you feed a SCART signal into it and also a UHF
feed?


It's the same fault if i feed it the cable TV through the TV's antenna
input, as well as if I feed it DVP player input through the TV's monitor
inputs.



Sounds like the old Macrovision thing. Picture alternately darkening and
audio fading due to copy protection embedded in the video signal (like from
a vcr or dvd player). Doesn't normally affect the RF input, only the raw
audio/video outputs of the player connected to the like inputs of the tv.

A capacitor issue would normally affect one or the other but not both at the
same time. A power supply cap might cause hum in the audio or hum bars in
the picture (or both).

A capacitor leaking on the board, on the other hand, could cause a variety
of problems.


Mark Z.