820-3437 no sound

[grmacs]

Everything else appears to work. After reading another thread, found this also has 0V at HDA_RST_L with IO board and cable connected. I've been unable to identify why. REsistors R131X all look good. Tried multiple I/O in boards and cables to no avail. It looks like most of the lines from j9500 go directly to the PCH. I've been bitten by the PCH snake a few times lately.

Checked connections at bottom of J9500 and that they are pinging at cable connection end. I have PP1V5_S0SW_Audio at J9500 also.

 

[2informaticos]

Audio codec does not even recognized?

 

[grmacs]

Correct. No options listed in audio settings. Pushing volume buttons shows speaker with not allowed/available? symbol.

 

[2informaticos]

Audio codec is placed in LIO board.
So try known good LIO board and flex.

 

[grmacs]

I already tried known good boards/flexes?

 

[2informaticos]

HDA_RST_L must be 1.5V.

 

[grmacs]

So does PCH detect with HDA_SDIN0 before giving 1.5V on HDA_RST_L? OR any guess what voltages signals must be going in to produce that output?

 

[2informaticos]

No communication is possible between PCH and audio codec, until reset signal goes high (disabled).

 

[grmacs]

Somehow I have 1.4V at HDA_RST_L now is over 1V enough?
Still no options show in sound devices

 

[2informaticos]

Should be good now.
Possibly bad contacts in the LIO connector of MLB.