MAcbookPro 820-01598-A no image no chim

[Praveen Sahwal]

Hi
I have a MBP 820-01598-A with liquid damage. I tried by cleaning and replacing some damaged or rusted components and finely it start taking 120-150mAmp but no image and no chim. Then i got to know that CPUGT_PWM1 and PWM2 are not present on U7410 & U7420.
Then i check U7100 which looks good and also i removed it and soldered back but still nothing happens. What else i need to do?

 

[2informaticos]

First of all, welcome to the forum!

PPVCCGT_S0_CPU only appears under heavy graphics load.
What about PPVCC_S0_CPU and voltage on other big coils?

PLT_RST_L comes high?

 

[Praveen Sahwal]

Thanks for your quick reply
U7100 was short with pin 41 PPVIN_S0_CPUVR_VIN so i replaced that i am getting CPUCORE_FCCM-2V but no response at other points. i don't have list of power rail in the schematics. i checked randomly these power rail.
PPVCCIO_S0_CPU---0.9V
PPVCC_S0_CPU--0V
PPVCCGT_S0_CPU--0V
PPVCCSA_CPU_R--0V
PPVCCEDRAM_S0CPU--0V
PLT_RST_L is Low
PP1V2_S3--1.2V

 

[2informaticos]

As I said, forget about PPVCCGT_S0_CPU.
But PPVCCSA_S0_CPU must appear before PPVCC_S0_CPU.

Post exact ohm value to L7702, L7210/20/70.
Compare with other board, if possible.