I will spare you the technical details…
If you have a PO that does not power on, or one that powers on but resets when you press a button, grab a pair of tweezers and bridge the pads below. If it starts working, solder a wire in place.
I literally just repaired 10 dead POs with this fix.
Best of luck.
The 5 pin ICs next to and above the appear to be voltage regulators, but the 3-pn IC is only connected to the one above. It’s possible that it’s for reverse polarity protection.