Mitsubishi LT-46249 no audio help

[Solderjerk]

I have a Mitsubishi LT-46249 with no sound, video is fine, that I'm runnng out of ideas with
Video is fine, no sound out of speakers ( it has 16 built in speakers )
Besides all the obvious menu setting I plugged a Bose into the audio output of the tv...no sound. Put the tv in service mode that has a output test to static the speakers one by one...no sound (neither internal speakers and Bose)
Dug up the schematic, see attached, I checked all the hots (red lines)on this drawing and can't find a bad one...V is good everywhere. The audio circuit is part of the main board if that matters
So it must be a trigger somewhere that fires the audio I'm guessing...but I suck at audio signals so I'm not sure. Any idea how this circuit works...like I said I don't think it's a “amp” problem as far as source power goes...I'm lost

[R_J]

Re: Mitsubishi LT-46249 no audio help

Can you connect the optical output to an amp? that would eliminate most of the auidio output section of the tv.

[Solderjerk]

Re: Mitsubishi LT-46249 no audio help

Can you connect the optical output to an amp? that would eliminate most of the auidio output section of the tv.

It doesn't have one...just analog out

[petehall347]

Re: Mitsubishi LT-46249 no audio help

does it have headphone socket ?
i would be checking power supply to audio section .

[R_J]

Re: Mitsubishi LT-46249 no audio help

It does seem to have a digital audio output and a digital audio input (going by the manual) and looking at the block diagram it would be the easiest way to narrow down the problem.

If you press the info button what does the display indicate (location 2)

[Solderjerk]

Re: Mitsubishi LT-46249 no audio help

does it have headphone socket ?
i would be checking power supply to audio section .

No headphone socket
I did...like I said if you look at that pdf I checked pretty much every red line which is the power flow

[Solderjerk]

Re: Mitsubishi LT-46249 no audio help

It does seem to have a digital audio output and a digital audio input (going by the manual) and looking at the block diagram it would be the easiest way to narrow down the problem.

If you press the info button what does the display indicate (location 2)

I was thinking optical but yes that is the back panel and it is rca dig out...I don’t have anything for that I don’t think, but I did plug it into the Bose input and got nothing...of course I don’t have a converter
2 shows surround sound

[Solderjerk]

Re: Mitsubishi LT-46249 no audio help

So yeah dig out does bypass everything

[Solderjerk]

Re: Mitsubishi LT-46249 no audio help

I’ll see if I can dig up a digital converter...i probably have one somewhere in the junk pile

[R_J]

Re: Mitsubishi LT-46249 no audio help

If you plug the digital audio out into the analog input of an amp I believe you should at least hear digital noise. If not I would think the problem is with IC4A02 or how its configured or a software/firmware problem. If you do here digital noise, try feeding the digital out back to the digital input.

[Solderjerk]

Re: Mitsubishi LT-46249 no audio help

So I found a converter plugged it in and the sound works....nice
So now do I just go with the converter or try to troubleshoot the ic4a02??? Worth it or not??.
My bad on missing the dig out jack...sorry and thanks