820-00165 SMC Resets when physically touching U5110, and U7090, and its surroundings.

[StraightToThePoint]

When I touch, with my finger, U5110, or U7090, the SMC will reset

Its actually seems like the SMC turns on, then off, then on again.

This board had a history of liquid damage, there seems to be no damage around U5110, and its surroundings, however on U7090, the chip itself seems fine, but C7094 seems like it has been charred, however is still outputting correct voltage.

The Macbook does have fan spin, but does not power up or show image, CPU gets warm though. Fans spin really fast too.

 

[2informaticos]

Do you get correct and stable 3V42_G3H?
AVREF_SMC is good?

Change C7094, it is very important.

Did you test for USB activity (both ports)?
PLT_RESET_L and PLT_RST_BUF_L go both high?

 

[StraightToThePoint]

Yes I get a stable 3.4V

AVREF_SMC reads at 3.2V which is the same for me on a working board.

I will change C7094.

No USB activity at all. I have already removed J6100 due to corrosion, and U6100 looks fine.

 

[StraightToThePoint]

I may be mentally handicapped... You can reset this on a working board by using your finger

But still, no image, and the fan does spin to the max. I replaced C7094, U5110, and U7090, so we know for sure thats good.

 

[2informaticos]

U5110 inputs are very sensitive; if you touch them, can trigger the output reset.

Corrosion near J6100 could affected opposite side.
Check all SPI Bus Serie Termination resistors and traces.
Also try FULL known good working BIOS, with clean ME.