Machook Pro - 820-2879

[vaswaniraj]

Hi Team,
I have received a Macbook Pro 820-2879 where the computer works fine, just that the Audio does not work. If gone on System Preferences >> Sound >> Output >> No output devices found. Input >> No input devices found. I thought that it could be a Software issues, so I went ahead and reformatted the hard drive and set up the computer as a New computer without customers data. Still the computer does not show any output and input devices. Can you help me in solving this issue.

 

[ALB-Repairs]

is PP4V5_AUDIO_ANALOG present?

 

[vaswaniraj]

No. PP4V5_AUDIO_ANALOG is not present.

 

[ALB-Repairs]

thats your problem, restore that and youll be good, check for input, whatever enable thats required and shorts on output.

 

[dukefawks]

4V5 analog does not need to be present as that only powers the amps/analog side of the chip. The digital side is not working as it is not recognized in the OS. Is there 5V on L6200? Check power on L6201 too.

 

[vaswaniraj]

Hi Duke, No I am not getting 5V on L6200 and on L6201 as well I am not getting any voltage.

 

[aprendiz]

5V on L6200 comes from PP5V_S3 which of course should be present otherwise the machine would not work...

If you have 5V on pin 1 from L6200 but not on pin 2, just replace L6200..

But if you dont have voltage on any pin of L6200 maybe it is a broken trace, fix it if you find it or run a wire from pin 1 of L6200 to the closest pad where you find PP5V_S3..