This is a waterdamaged board with damage around the battery connector area. I get PPbus_G3h, green light on charger, PP3v3_s3 is there as well, but no _s4 power rails. PP5VS4_EN on U7501 is only 0.4 V. Also resistance to ground on PP3V3_S5 is 50 ohms measured from L7560. When i plug in the charger U1100 gets hot, so i suppose this is the culprit. Are these chips generic? or do i need one from a donor board?