Z5WAH LA-B162P keeps burning its PU401 IC

[kalilinux25]

Hi this board has a bad step down voltage regulator ic so I ordered the IC then change it but it keeps shorting again

[mcplslg123]

Re: Z5WAH LA-B162P keeps burning its PU401 IC

You probably have some shorted component or if it was burnt, then ground issue. Check resistance specially on pin 5/7/8

[kalilinux25]

Re: Z5WAH LA-B162P keeps burning its PU401 IC

You probably have some shorted component or if it was burnt, then ground issue. Check resistance specially on pin 5/7/8

i get a normal resistance in the pins but why it keeps shorting

[piernov]

Re: Z5WAH LA-B162P keeps burning its PU401 IC

No short to ground on +3VLP, +3VALW or any derived rail?

[mcplslg123]

Re: Z5WAH LA-B162P keeps burning its PU401 IC

i get a normal resistance in the pins but why it keeps shorting

There is some short on some rail-thats for sure. Short doesnt mean zero resistance always. Like say VIN of an IC is 19V and normally it should show infinity in diode mode but for some short it may drop to say 700-800 and this will keep IC burning. 3V rail as suggested by piernov is the likely shorted rail.

Open jumper PJ401 and measure resistance on both sides of jumper.

[kalilinux25]

Re: Z5WAH LA-B162P keeps burning its PU401 IC

I test the apj401 in both side the other side is 3 kilo ohm the other side 5 megaohms

[Iampityu]

Re: Z5WAH LA-B162P keeps burning its PU401 IC

I have a similar problem with the same mobo.... The pu401 IC gets hot after a few sec. And i have short on the 3v rail... How can i separate the problem??

[rein2017]

Re: Z5WAH LA-B162P keeps burning its PU401 IC

I have same board and same issue too, does anyone had fixed this?

[huzo]

Re: Z5WAH LA-B162P keeps burning its PU401 IC

i have a simmilar problem,the board is dead,i have 3V and 5V,and when i short 2 pins on the power button board that go to the hall sensor,laptop works and charges the battery,but the PU401c gets hot,when i remove the short it powers down...no shortcircuit on the board ....anyone found out something about this problem?

[taroo]

Re: Z5WAH LA-B162P keeps burning its PU401 IC

+3ALW is shorted and don't found
PLS advice PU601 also short on Pin 7