820-00928 dead.

Hello everyone, I have a small problem.

On my desktop, I have an 820-00928 motherboard, with no image, no chime, no USB activity, and no external video.
The CPU and GPU heat up normally, and the battery charges at approximately 4 Amps. PPBUS_G3H 12.62 Volts.

Previously, it was damaged by a liquid spill, affecting the U3100 chip. An ultrasonic cleaning was performed, which turned out quite well. Some time later, the computer began to suddenly shut down, and the customer thought the battery was failing. The battery was replaced, and within a couple of months, the computer began to fail again, displaying the same error: sudden shutdowns, irregular startup, and the current failure.

The strange thing is that I installed a good, original battery. The computer turned on normally once, and after that, it didn't work again.

These are the values for the large coils.

L7410: 0.008 v
L7420: 0.008 v
L7211: 0.966 v
L7221: 0.966 v
L7231: 0.966 v
L7330: 0.933 v
LA640: 0.906 v
LA650: 0.906 v
LA350: 0.910 v
LA300: 1.354 v
L7030: 12.67 v
L8000: 1.014 v
L7960: 0.974 v
L7900: 1.205 v
L7660: 3.315 v
L7600: 5.13 v
L8410: 0.020 v down
LB700: 0v

Please could you guide me or enlighten me, thank you very much.

CPU core stuck at 0.966V means the board didn't boot.
When boots, should drop to 0.65V aprox.
PCH, CPU and BIOS are involved there.
Possibly accumulated crap underneath BGA chips.

Thanks for the advice.
I found corrosion on the U9850 chip, and now I have 0.650 on L7221, L7211, and L7231. But I still have no image or activity on the USB.

Is there still hope?

All USB ports without activity?
Did you also check for external video?

yes, no activity in ports, no external video, no chime. the CPU and GPU get hot. the mousepad clicks. without the U9850 it should still turn on?

U9850 is not involved in power on sequence at all.

I'll remove the chip and test it. If it doesn't work, I'll bury it with the others.

I have an idea that the computer doesn't allow booting with external devices for that reason there's no USB activity. Another idea is that the chip in question has something to do with the LCD panel.

Machine doesn't need to boot from USB, to test external activity.