Acer Nitro 5 LA-F951P - zwarcie

Witam

Laptop: Acer Nitro 5 AN515-53
PCB: DH5VF LA-F951P Rev:1A
CPU: SR3Z0
GPU: N17P-G0-A1
Mostek: SR40B
KBC: KB9022Q D

Płyta ma zwarcie. Po podłączeniu pod zasilacz laboratoryjny załącza się zabezpieczenie. Wstępnie uszkodzony (fizycznie wypalona dziura) układ PU1501 (Z5038QI). Układ wymieniłem, po podłączeniu pod zasilacz zwarcia nie było ale jak zacząłem ją włączać kilka razy to w końcu znów doszło to tego samego efektu czyli zasilacz się zabezpiecza.
Obecnie nagrzewa się PU1501 (Z5038QI) oraz mosfet PQ311.
Proszę o pomoc bardziej doświadczonych Kolegów w namierzeniu usterki.

Pozdrawiam

as PU1501 is for +VGA_CORE I would expect it had shorted input/output and as result dead GPU (20V goes directly to +VGA_CORE) ...and next this short goes to +19VB_NVVDD over PL1502/PL1503 to +19VB... thats why PQ311 is heating(could also be shorted already) ....for test purposes you can remove/open PL1502/PL1503 to run mb without +19VB_NVVDD line.

Hello wof thanks for answer!
I removed PL1502 and PL1503 and motherborard run with image on the matrix. Now the laptop can work normally but without an external graphics card?
In this case, can I be sure that the N17P-G0-A1 needs to be replaced?

you can do "shortcircuit test" in +VGA_CORE line, but most probably GPU is KO and is causing short and blow of the power IC....before placing new GPU, replace both PU1501/PU1502 and check +VGA_CORE line work and other corresponding gpu lines, especially resistances without gpu - be sure you dont have another fault (..like VRAM etc)...

to short circuit test I have to install PL1502 and PL1503 next remove PL1501 and give 0.8V to pins 3,4 of PL1501 to what value should I give the current?

dont install PL1502 and PL1503 - let the shorted branch be disconnected from rest of the board....before doing test, remove already shorted parts (...PU1501, ???), start with current around 1A

At what point should voltage be applied during a short circuit test?

you are testing shorted +VGA_CORE line - it starts on output of PU1501/PU1502 ....you can connect to any suitable point in this line, doesnt play role which one..I would go behind PL1501/PL1504