820-3662 liquid damaged no power

[bighead]

Hi All,

So I have this nice Retina here with liquid damage.
I cleaned it. Battery is dead.

It was powering on, but no CPU VCORE.
I checked the power to U7200 and I saw R7202 was corroded. I changed it and it turned on for a sec or two and turned off.

PP3V42_G3H was 70-80 Ohm short to ground. I found a bad corroded cap C1950. I changed it with U1950.
It turned on for a second again. I was able to turn it on with SMC bypass, but after 10 seconds it turned off. Never could turn it back on.

I found SMC crystal wasn't oscillating and there was no voltage on it. No short! I didn't have the same board so I took the SMC off of the 820-3332.
After I replaced the SMC the crystal is oscillating, but still not turning on. The fan just barely spins up. This is not a turn on-off loop thing.
This tries to turn on, turns off and it does not try to turn on again. I tried SMC bypass mode, but same thing. I couldn't find any short.

It still powers on if I remove R7202, just of course no CPU VCORE.

Any ideas?

Thank you!

 

[dukefawks]

Start with using the correct SMC. The original one is probably fine, was just crap under it.

 

[bighead]

Well, I received the parts board for this board. I changed the SMC with the correct one, but still no power.
I lifted all CPUVCORE coils at the CPU side and checked them if I have anything on them without connecting it to the CPU.
With multimeter is show 3V which is extremely high. I checked with scope and it shows the PWM wave on both side of the coils. All of them(3).
How is that possible?