Acer C27-1655 no power after liquid damage

[bloodhound]

Hi!

I´ve got an Acer C27-1655 AiO computer for repair on my bench.
Mainboard: AX1T_MAIN_PCB

The liquid was mainly in the area of MQ1, the voltage regulator for +VDDQ_MEM (pictures attached).

Symptoms:
When power is connected and power switch is pressed, I get 5V at L1, 3.3V at L2 and 1.8V at LPM5. I also get V1.05A_BYPASS at R442 for PCH.
I also measure 2V on +V1.8U_2.5U_MEM but +VDDQ_VTT and +VDDQ_MEM stay at 0V. +V1.8U_2.5U_MEM is also drawn to 0V if RAM memory is installed.
LPM1, LPM2 and LPM3 stay at 0V.

+VDDQ_MEM & +VDDQ_VTT don´t show any shorts to ground.


I don´t know if it is normal or not in this stage of the power cycle, but PCH/CPU gets a hotspot with about ~50 °C.
In my opinion, the liquid in the area of MQ1 led to a overvoltage at the memory voltage part, causing a fried PCH.

What do you think?
Do you have any suggestion?

[bloodhound]

Here is the schematic of the board: Schematic moved to new thread - https://www.badcaps.net/forum/troubl...1655-schematic

[mon2]

PCH/CPU gets a hotspot with about ~50 °C.

Usually a show stopper but wait on other comments.

[bloodhound]

I might have come to a conclusion a little too fast.
I didn´t see, that the buck converter is fed by +V5A and +V_DC.
I measured these and I get everything. So +V5A, +V_DC and also +V3P3A is there:


So it´s possible, that only the buck converter is busted.
What do you think?