Hello

I need help with this problem. i have no clue what to do next.

Please read all what i have changed and did...

model with 37w cpu

motherboard came in shorted, no 19v power line
i have desoldered coils to find a short. when i removed PL901 inductor i got normal 19v on the charger, since it is power supply for the CPU i had 3.3v on the power button and 3.3v standard on battery charge.

i have bought all of the mosfets and the controller (couse i did not have spare parts or controller or donor board)
new pu901 controller
new pq902 pq901
new pq 905 pq906

i haVE changed them and tested for short to ground , there was no short.
i have put back the inductor pl901 and tried to turn the motherboard on. motherboard did not turn on, and the board close to the pu901 (controller started to heat up, maybe the chip itself got warm)
i have measured the voltages on the power button and it was 3.3v as usual and normal battery charging signals.

30 seconds later i wanted to measure it all again and i had short again...
i have replaced all the same chips (couse i bought 10 of each just in case)
but short remain
i have removed pl 902 , pl904 and pl903
and replaced controller pu901 again
i have found capacitors ( tantalum i believe) 330uF to be shorted pc954 pc957 and pc960
i have replaced them with 330uF capacitors and had no short again.
i have put back the inductors back and again same shit, the capacitors blow.

i have did this 3x
i have removed and tested resistors 10ohm which send back the current read from the end of the inductors to the controller (they are all 10ohm, so good)

what to do ? anyone has any clue? this is second board ive got with this problem, the first one had majoy damage and shorted cpu vcore...

Hello Drago.
Do you have a regulated power supply unit? You can use it to find where short circuit is, if you know how to do it.

No, it`s wrong way !
draganzile, is PU902 ok? Try to replace it;
then BST1, BST3, VR_SVID..

this is model with i5 4200 processor, it does not have pu902 chip couse it is up to 37W TDP , only model with i7 4700 have pu902

bst1 bst3 resistors are both 2.2

i have checked the capacitators in the resistance mode and they are not shorted...

im gonna check VR_SVID in the morning. i do not have much experience in this. i can find short in controllers, mosfets and other stuff, i have never tested the controller feedback :(

if you have any other suggestions, please say now. i will retest it all in the morning, gonna replace all of the chips again and then will retest feedback.

is it somehow possible that 5v power rail when gets to the PVCC pin somehow fucks up with the capacitator pc914?