I must correct myself. I don't know what I messed up while measuring before, but now PU2 [I]does[/I] actually have 3.3V on its output. However, PQ8 only has 3.3V on its drain (see page 50 of the schematics). If I understand it correctly, this MOSFET is switched on when 3.3V_ALW is present, which is powered by PU100 (page 51). For PU100 to work, PWR_SRC needs to be present, and that brings us back to the ISL9538H (PU901) and its surrounding circuit. Does that make sense, or am I missing something?I must correct myself. I don't know what I messed up while measuring before, but now PU2 [I]does[/I]

Thanks for the suggestion. VIN has 19.5V, all other pins have 0V. The VOUT pin has about 100K resistance to ground, so there's no short there. I'm guessing that voltage regulator is dead then? I couldn't find a perfectly matching replacement chip in my collection of dead motherboards. The closest thing I found was a G920AT24U, which is the right voltage but doesn't seem to have the same current handling capacity as the RT9058-33GX (see attached datasheets), so it's probably best if I just order the correct chip....

Hi,

I have a Dell Latitude 5590 with motherboard LA-F411P Rev 1.0 that has liquid damage and doesn't turn on anymore when only the charger is plugged in. However, it does turn on when powering it from a battery. I couldn't find schematics for this exact board, but LA-F401P seems to be similar (that post says LA-F411P, but the attached schematics are actually for LA-F401P): [URL]https://www.badcaps.net/forum/troubleshooting-hardware-devices-and-electronics-theory/troubleshooting-laptops-tablets-and-mobile-devices/schematic-requests-only/98588-ddm80-la-f411p-schematic-or-boardview-needed?p=3262678#post3262678[/URL]...

Hi, I don't have any background in electronics, but I like repairing things, and the resources on Badcaps have helped me a lot already.