A1286 - LOGIC BOARD 820-2523-B - NOT BOOT

[fabry79]

Good Morning,
i'm Fabrizio From Italy

I'm a newbie about logic board repair ,
and i require you a little help.

I've in my hands a macbook pro a1286 - motherboard 820-2523-B ,
no boot - black screen.

With magsafe and battery connected i've green light of led and after orange light that confirm me battery recharge.
after SMS reset + PRAM reset , the fans start at maximum speed for a few seconds , then macbook turns off.

with only battery connected the macbook doesn't start.

The IRF6710 and irf6795 are really really hot..


The GPU is a NVIDIA MPC79-MXT-B3.

I don't understand where is the problem...
Can help me?

Tnx for your attention and greetings from Italy,
Fabrizio

 

[fabry79]

Tested following resistors :

R7120 -> OK
R 7112 OK
R 7121 OK
R7100 OK
R7101 --1.58 kOHM ( ISTEAD OF 3.65 K)
R7106 --1.58 kOHM (ISTEAD OF 3.65 K)

 

[fabry79]

hi,
in the meantime I bought the IRF MOSFETs.
when they arrive, I will proceed with the replacement..
other suggestions? hasn't happened to anyone?

 

[fabry79]

Changed IRF6710 ..
now i've 0 volt on all test point of the U7100

battery charge normally ....( green light on magsafe , and after orange)

Can Help me?

 

[fabry79]

hi, where is located C2560?