820-3476-A no audio (no chime, no audio devices detected)

[protocold]

No chime. MacOS will not detect any audio devices (settings no mic/in/out).

Where do start?

 

[2informaticos]

Any history available?
Check U6201 power rails; start with U6200.

 

[protocold]

Other than sound. Everything else seems to be ok so far.

C6411 got knocked off and U6410 seems to have a little chip around the corner (at pin1)

U6200:
pin 1 (PP4V5_AUDIO_ANALOG) = 4.5v
pin 3 (4V5_NR) = 1.2v
pin 4 (4V5_REG_EN) = 3.3v
pin 6 (4V5_REG_IN) = 5.1v

PP3V3_S0_AUDIO_ANALOG - 3.3v
PP5V_S0_AUDIO_AMP_L - 5.1v
PP5V_S4_AUDIO_XW - 5.1v

L6300 = 1.5v

 

[2informaticos]

Check resistors and traces between PCH and audio coedec; like R6331, etc.
If all good, change U6201.

 

[protocold]

checked R6331. R1310, R1311, R1312, R1313 they are all good. Is there any other that I missed that I should check before changing U6201?

 

[2informaticos]

Change it now.
Be sure to get good solders...

 

[protocold]

sorry to dig up this old thread. I have changed the U6201 but it still the same...

 

[2informaticos]

Check its power rails.

 

[protocold]

PP1V5_S0_AUDIO_DIG = 1.5v
PP3V3_S0 = 3.3v
PP4V5_AUDIO_ANALOG = 4.5v

 

[2informaticos]

If audio codec is still not detected, then bad chip/solders.
Also check all resistors and traces from its area; even on the other board side.