panasonic tx-37lzd80 picture but no sound

[adamp91gvm]

as above i have a spot on picture but no sound at all i have checked the settings but nothing i have tried headphones in and even at full wack there is just the slightest sound if u listen close

[tom66]

Re: panasonic tx-37lzd80 picture but no sound

Picture of the A board? Have you checked if PSU is giving you all voltages? I have a memory that these have a 12V and 17V line, the 17V is audio only. If that went dead no audio. Also there are usually separate regulators, one for audio. You'd need to check to be sure.

[adamp91gvm]

Re: panasonic tx-37lzd80 picture but no sound

[adamp91gvm]

Re: panasonic tx-37lzd80 picture but no sound

Do u need a pic of the back

[tom66]

Re: panasonic tx-37lzd80 picture but no sound

Have you checked any voltages? From memory, they are labelled.

[adamp91gvm]

Re: panasonic tx-37lzd80 picture but no sound

No markings that's why I'm stuck

[Caleb]

Re: panasonic tx-37lzd80 picture but no sound

Attaching service manual should help finding the spots to look at on the main.

[budm]

Re: panasonic tx-37lzd80 picture but no sound

Does it have line level RCA (RED & WHITE) audio out put jack that you can use to feed power PC speakers or stereo to see if you do have normal sound, that way you can tell if the problem is in the pre-amp or in the power amp sections.

[adamp91gvm]

Re: panasonic tx-37lzd80 picture but no sound

I have tried it through my surround sound and nothing is coming out

[tom66]

Re: panasonic tx-37lzd80 picture but no sound

Have you checked the digital optical audio output too?

[adamp91gvm]

Re: panasonic tx-37lzd80 picture but no sound

I ain't got one to try it with

[tom66]

Re: panasonic tx-37lzd80 picture but no sound

K, time to check voltages - the schematic will have the P board voltages on it listed.

[adamp91gvm]

Re: panasonic tx-37lzd80 picture but no sound

I'm looking at them but can not see where the amps are for the speakers or where to test

[tom66]

Re: panasonic tx-37lzd80 picture but no sound

Page 10 has voltage test points...In addition run page 11 selfcheck - will reset TV - see if that sorts it.

[adamp91gvm]

Re: panasonic tx-37lzd80 picture but no sound

On self check it says adav ng and said that the self check failed

[tom66]

Re: panasonic tx-37lzd80 picture but no sound

NG = "No Go". Would seem to indicate a problem with whatever ADAV is, or one of the power supplies leading to it. My guess would be the smaller Analog Devices chip, top right hand corner.

[adamp91gvm]

Re: panasonic tx-37lzd80 picture but no sound

[adamp91gvm]

Re: panasonic tx-37lzd80 picture but no sound

Any test points I can check ?