820-4924 No Audio

[ALB-Repairs]

820-4924 that has had its audio jack replaced elsewhere. Showing no audio devices in OSX (no chime either)
I have replaced the codec (u6201) twice, and still pin 4 of J6600 (jack) is O/L instead of 780 ohms (same with both codec's)

Ive followed the line and found no bad traces (but have not checked the pad under the codec, but the BGA site looks clean without damage).

Im not sure i want to lift the codec and have to re-ball again. But something is wrong. I am also worried because it shows no audio devices in system report.
Anyone got any ideas?

 

[ALB-Repairs]

Oh yeah, i forgot to say, All the power lines to the Audio codec are fine!

 

[2informaticos]

Codec should appear in system report, even if bad audio jack...
However, check all small coils L660x.
Also check for other knock off components, reball chip if you are not sure about solders.

 

[ALB-Repairs]

Ive checked all small coils.
The jack is not bad, The codec has been replaced twice and im pretty certain of the soldering.
Ive checked against other boards for knocked of components, i did find a bad 5V trace to the amplifiers and repaired that, however that will not fix the codec not being recognised in OSX.

Does anyone know how OSX communicates with the Codec? I think its through the HDA lines?

 

[2informaticos]

Yes, HDA_ lines, but audio codec should be in conditions to talk with PCH.
Check frist high level at HDA_RST_L and R6331.

 

[ALB-Repairs]

Fixed, seems i messed up the codec twice. Wasnt soldering very well that day.