TV sound volume decreases as picture gets dark

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

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

Reply to
N_Cook

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.

Reply to
Joe

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.

Reply to
Mark Zacharias

If you want to confirm a Macrovision problem, if possible take a video out put signal of the program before it hits the TV and run it through a D to A converter such a s a digital video mixer. What comes out should be stripp ed of macrovision. Then feed this signal into an AV input on the TV. Lenny

Reply to
captainvideo462009

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