00840 audio issues

[captainmac]

00840 with no liquid damage
came in for a screen-replacement (original screen had one crack in it, so no heavy damage)
So this one has no audio
(no audio input/output devices in Sound preferences, and under systemprofiler there is only listed: Devices, Intel High Definition Audio. Audiocode: 0 ).

I measured around U6200 and verified all the VINs were present
diode-mode checks on HDA lines all look fine compared to a workingboard

So i figured then it must be the chip, so took one from a donor
Than just to be sure i also replaced U6300 as the reball-gods were good to me, so i replaced both u6200 and u6300.

All to no avail: i still have the exact same problem

any ideas what to check next?

 

[2informaticos]

Try another audio baord.

Posibbly knocked off, or broken components.
Did you check HDA_RST_L?

 

[captainmac]

this doesnt have an audio board, but you know that

HDA_RST_L is 1.8V

 

[2informaticos]

I talk about the board where audio connector is placed; connected at J6600.
It manages some audio sense signals.
Shouldn't be an issue for non-recognized audio codec, but is worth to try...

 

[captainmac]

ok, yeah the jack you mean. yeah i couldve thought of that myself dammit. havent tried that, will do and report back monday.

 

[captainmac]

ok, tried it with a different audio jack, but no dice..

 

[2informaticos]

If audio was good before screen replacement, then should be some knocked off component, or broken.
Now can be also something wrong with changed chips.

 

[captainmac]

i diodemode tested around U6300 to find L83_VP was measuring full short
the pin was connected to ground in the chip itself.
Must've been a crap donorboard. anyways, everything is working again, thanks for the help!