820-00165 No S0, SYSCLK(s) trying to turn on, corrosion all over

[G.Beard]

Where is the origin of the audio signal?... I mean before amplification or anything.

 

[G.Beard]

The OS does at least know there is an audio device it just does not output any audio.
Probably put this board to one side for a day or so now.

 

[dukefawks]

SPKRAMP_SHDN_L high? Verify voltage on C9520.
If you can change volume in OSX data to audio chip is ok. Try with a headphone too.

 

[G.Beard]

C9520 = 1.5V
SPKRAMP_SHDN_L = low = 0V
Yes level shift on volume but no Headphones output or speaker. Get audio on BlueTooth.

 

[dukefawks]

Well SPKRAMP should be high! Is generated on the IO board. Did you check all HDA lines at J9500 on diode mode? AUD_PWR_EN high?

 

[G.Beard]

Well SPKRAMP should be high! Is generated on the IO board. Did you check all HDA lines at J9500 on diode mode? AUD_PWR_EN high?

SPKRAMP: New IO on the way in case all my IO boards are fucked which is possible I guess.
HDA lines on J9500 no shorts.... Are you asking exact drop across each?
AUD_PWR_EN high.

I live in hope that I am a complete numpty without a working OI as I may have swapped them all out. Get back in a couple of days. Actually amazed this board boots at all
Thanks for your help

 

[dukefawks]

SPKRAMP not being pulled down by the board? bad U6410, measure diode mode.

 

[G.Beard]

SPKRAMP not being pulled down by the board? bad U6410, measure diode mode.

SHDN low
Just found that a pads that "looked" there, are actually not there. SHDN and GAIN
I will replace U6410 and test diode mode etc.

Double checked continuity to all pins to J9500 back to anything audio and all good. Resistors OK, no shorts.
No headphones, is bluetooth, internal is recognised and volume shift.

I wonder if tying SHDN to PVDD will work

 

[dukefawks]

Analog section of the audio chip must not be powered. Only power source I see for that is pin 9 or 28. See if R9501 is really no stuff and check continuity of pin 9 through the connector/cable to the io board.