Hi everyone..

This laptop came with no power at all, no +19v on the input, someone was missing with the input Fets, PQB12 & PQB13 aren't on the board, according to the images from the forum there should be EMB12N03 which I don't have so I've used P0903BEA, it doesn't work...

There's 19v on the drain of PQB11, at the source it jumps 0v~0.7v, the gate also jumps 0v~0.7v, I've noticed they've installed AON6426 on PQB11, according to the images it should be EMB04N03 which also I don't have... replaced with 4955N and it's still won't work..

Replaced PQB12 & PQB13 with B20N03, still won't work...

There's no short on the 19v or anywhere else..

Could it be an incompatible Fets or they should start ? if they're not please give some equivalent

I've found the gate of PQB11 is connected to PUB1 (BQ25A), replacing the charger didn't help..

I've took a tip from the forum to use the lowest possible RDSon so I've replaced PQB11 with MDU2653 (Rdson 3.5mohm) and still nothing, removed PQB12 and +19v appeared on PQB11's source with 25.5v on it's gate..

resistance at PQB12's drain (@PRB1) is 182 ohm ???
resistance at PQB13's drain (@PRB11) is 159k ohm

replaced PUV1 (RT8812A) didn't help also... where to dig ?

edit: using B20N03 on PQB12 & PQB13

Oops..
Well i was wrong, there is a short on 19v




Well, I've found a shorted dual-mosfet PQM1 marked "K4 AUB" (pe642dt it is), removed it and 19v appears across the board

PLM1 & PLA1 have very low resistance, PLM1 1.2 ohm, PLA1 1.0 ohm (reference is 0.7 ohm), and since there's no schematic for this board it appears that PLM1 is powering RAM and PLA1 goes to the CPU "SR3LC"

I don't have a similar mosfet, I've tried the much lower power AON7934 but it fried immediately..

injected 1.2v in PLM1, 2.1A consumed and nothing heats up, barely the CPU warms

injected 1.0v in PLA1, 4.1A consumed and nothing heats up, barely the CPU warms

is it normal resistance for SR3LC chips or I have a dead memory controller here ?

No answer found..

I believe the memory controller is shorted in the cpu, will close this topic..

Thank you