Dell inspiron 15 shorting out charger (la-9104p) keeps blowing mosfet

[gcomputers]

Re: Dell inspiron 15 shorting out charger (la-9104p) keeps blowing mosfet

-Pq100 & PQ101 (ac_fet), if one of them shorted then that indicate there's have problems with B+ (19v)or to much high current flow with it. a bit experience, also could be followed with other components has shorted.
could be bad caps, mosfets or ic chips.
-B+ spread to dc/dc 3.3v/5v, also to high side mosfet each dc/dc's, and reach to connector ldvs
-make sure before do replacement, the short circuit on B+ has gone, you can check resistance versus ground on the empty pad after you had removed components
-if want to inject with psu, not over than 1v . except you know there's no high side mosfets dc/dc has shorted. a little trick, if you want to increase voltage psu, while that do measure on coil cpu core, 1.05v (that has just low volatages). if you've find voltage on a coil, so high side mosfet has shorted.
-you see on schematic. 19v transform to other name vin>>>>p2>>>>>p3>>>>>B+>>>>>CHG_B+ and B++ to rt8205, whereas same 19v
-at last, check Batt+ not shorted to ground

Thanks for the reply Meritosari .
removed PQ101 pin 5678 have 0.6 ohm shorted with ground, Pin 123 19.8V pin4 8,44V.

injected voltage with Psu 1v 8a but any component does not heat up. and on coil cpu have 5.9ohms and no voltage 0V.

Batt+ measured on PR121 are shorted with ground.

Any other help please

[gcomputers]

Re: Dell inspiron 15 shorting out charger (la-9104p) keeps blowing mosfet

Had same problem once on one of boards, turned to be pc502 in the circuitry of pq500. then the problem returned after a week later, the issue then was at the same circuitry but this time pc501. Ended changing all those four caps, device never returned back to me, may be to someone else!!

THANKS TIBD THANKS , SOLVED

PC502 burned replaced ok ALL FUNCTION
no more short on B+.


How you find it with PSU lab ?

[tibd]

Re: Dell inspiron 15 shorting out charger (la-9104p) keeps blowing mosfet

yes with PSU. I would recommend you change all those 4 caps, and preferably with at least 35 v rating, higher would be better.

[Mr repair]

Re: Dell inspiron 15 shorting out charger (la-9104p) keeps blowing mosfet

thanks my friend but no luck, still same problem.
I removed the shorted pq101 and replaced it with a ao4407,then removed the pl100. reconnected to laptop but it shorted out pq101 for the 5th time..

check and see if you are installing the mosfet the right way

[Nikosz]

Re: Dell inspiron 15 shorting out charger (la-9104p) keeps blowing mosfet

Hello,
i have 2 motherboards with exactly the same problem.
has anyone found any solution?
Thanks