820-3476A NO BRAIN

MacLab

New member
Hi guys, sorry about my English. This is an 820-3476A that arrived without power on.
The SMC looks reflowed and liquid damage around u7200.
I change u7200 and now the board turn on but not fan spin, no chime, and no usb activity.
I try a good efi bios and still no brain

PPVCC_S0_CPU. 1.74v
PP3V3_S0 3.3v
PP1V05_S0 1.05v
PP0V675_S0_DDRVTT 0.675v
PP3V3_S0 3.3v
PLT_RESET_L 0v
PM_PCH_SYS_PWROK 0v

Diode mode
PPVCC_S0_CPU_PH1 0.045v
PPVCC_S0_CPU_PH2 0.045v

Resistence
PPVCC_S0_CPU_PH1 40ohm
PPVCC_S0_CPU_PH2 40ohm
 

Mac Tech

Member
here may be the problem, this signal is generated by U5000 SMC. But some transistor may be blocking the signal. If I already change u1950.
 

MacLab

New member
here may be the problem, this signal is generated by U5000 SMC. But some transistor may be blocking the signal. If I already change u1950.
I suspect that the smc could cause the trouble because it was reflowed previusly.
Need a donor for this SMC. Soon update with the result. Thanks for the help
 
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