Alienware 17 (R5) shorted Mosfet

[Grishnackh]

Hello Guys,

i have a Problem with my Alienware 17 (R5), it´s the LA-9331P Board. I dont know excactly what happend with this Alienware i got it functionless. I detected that the Power Supply was faulty (it was a DA180PM111 19,5V / 9,23A), so the Notebook didnt started. I bought a new Power Supply, it is a mtXtec 0J211H 19,5V / 12,3A. When i pluged the Power Cord to the Laptop something blown. It was the PQ502 - MDU1516 which burn out. Could someone tell me what could be the reason? I measured the Voltage on the 0J211H, for less then one second i have about 30V, and then it varies between 18V - 22V.

Can someone tell me if the Power Supply is faulty? I checked the manuel of the MDU1516, he should take up to 30V max. So why is he blown?

Greets, Grishnackh

[dellxps15]

Re: Alienware 17 (R5) shorted Mosfet

we need schematic.

[polytek]

Re: Alienware 17 (R5) shorted Mosfet

check your cpu PQ502 cpu vcc
here is the sch:

[MOD EDIT] Link to schematic https://www.badcaps.net/forum/troubl...331p-schematic

[Grishnackh]

Re: Alienware 17 (R5) shorted Mosfet

Hello,

@polytek - thank you for you help, i measured the ohm - like shown in your picture - to ground, and it´s about 0,2 Ohm. I hope i did it correct, because it has only two pins (see picture). Should i measure the voltage too? I am afraid to burn another mosfet - i already removed the burned PQ502.

Greets, Grishnackh

[koresi]

Re: Alienware 17 (R5) shorted Mosfet

hello
where did you measure 0.2ohm?between pl501 and ground?
do this measurements(before that remove the cpu):
pq502 pin4 and gnd
pq502 pins1,2,3 and gnd
pq502 pins5,6,7,8 and gnd
pq502 pins1,2,3 and pins5,6,7,8

[Grishnackh]

Re: Alienware 17 (R5) shorted Mosfet

hello
where did you measure 0.2ohm?between pl501 and ground?
do this measurements(before that remove the cpu):
pq502 pin4 and gnd
pq502 pins1,2,3 and gnd
pq502 pins5,6,7,8 and gnd
pq502 pins1,2,3 and pins5,6,7,8

pl501 to ground -> 0,1-0,2 Ohm
pl502 to ground -> 0,1-0,2 Ohm
pl502 to ground -> 0,1-0,2 Ohm

pq502 pin4 and gnd -> 22 MOhm
pq502 pins1,2,3 and gnd -> 0,4 Ohm
pq502 pins5,6,7,8 and gnd -> 33 MOhm
pq502 pins1,2,3 and pins5,6,7,8 -> 19 MOhm

Greets, Grishnackh

[highpulse]

Re: Alienware 17 (R5) shorted Mosfet

No , if that mosfet is burning ITS BECAUSE OF u GATE AND l GATE , post values of does gates here please and also chek pc503 to pc507 , lift the mosfet that is burning , and remove the side one as well , and chek the capacitors for short . give us this infos , seems a easy fix , just needf to know values to give you right direction

[koresi]

Re: Alienware 17 (R5) shorted Mosfet

ok,so you have a shorted component on +vcc_core signal.you have to check all components connected on +vcc_core and ground.on the left side of pl501,pl502,pl503 you have pq503,pq504,pq507,pq508,pq5011,pq512,pu500.On the right side you have a bunch of capacitors :pc900,pc901....
if you can't measure the faulty one all you can do is remove one,measure,put it back and so on until the short goes away(the measurement has to be tens or hundreds of kohms).
goodluck.

[Grishnackh]

Re: Alienware 17 (R5) shorted Mosfet

Hello,

thank you all for your help so far....what i found out, is that PL501 seems to be defect or theres something wrong. I removed PL501, PL502 and PL503. Only PL501 (i called it "A") "A" has a connection to ground - that shouldnt be, "B" where connected with "B" from PL502 and PL503. PL502 and PL503 both "A" doesnt have connection to ground. When PL501 was on board, PL502 and PL503 also the little capacitors between PL502 and the CPU Socket were shorted. So i think i should go back the way from PL501 "A" - but which Pin from the Schematic on the PL501 (2, 3, 4) i should take?

Greets, Grishnackh

[koresi]

Re: Alienware 17 (R5) shorted Mosfet

pin4.
so only pq503,pq504 or pu501 is potential defective.i will go to pu501 (mosfet driver).

[Grishnackh]

Re: Alienware 17 (R5) shorted Mosfet

I think its PQ503 and PQ504 - both are shorted at least i have direct connection from Drain to Source. Is this my problem?

Other Mosfets PQ507, PQ508, PQ511 and PQ512 doenst have direct connection from Drain to Source.

Greets, Grishnackh

[Grishnackh]

Re: Alienware 17 (R5) shorted Mosfet

@Koresi i think you are right....on PU501 Pin 4 (GND) is connected to PIN 8 (PHASE3) and continue to Drain to Source from PQ503 and PQ504. So i could only be the PU501 or? Could anyone has information where to get this part in europe or a comparable to ISL6208BCRZ-T?

Greets, Grishnackh

[koresi]

Re: Alienware 17 (R5) shorted Mosfet

http://www.ebay.com/sch/i.html?_from...CRZ-T&_sacat=0

[Grishnackh]

Re: Alienware 17 (R5) shorted Mosfet

Thank you, i ordered it on aliexpress and the PU500 too - Do you think changing the PU501 will solve my problem?

[koresi]

Re: Alienware 17 (R5) shorted Mosfet

did you remove PU501 and short gone away?

[koresi]

Re: Alienware 17 (R5) shorted Mosfet

oh sh... yesterday I wrote pu500 instead pu501,my bad.it's about pu501 not pu500 ,sorry.
yes I think that changing pu501 will solve it.

[tata123]

Re: Alienware 17 (R5) shorted Mosfet

@ Grishnackh was genau war mit deinem Alienware, ging auch dein Netzteil nicht mehr?

Habe auch son änliches Problem...

Hoffe mal deiner geht wieder?

[Grishnackh]

Re: Alienware 17 (R5) shorted Mosfet

@koresi Thank you, i removed the PU501 and the short circuit is gone...hope to get soon the new one to test it.

@tata123
Ich kenn die Vorgeschichte leider nicht, ich habe das Alienware defekt gekauft - lt. Verkäufer war das Mainboard defekt bzw. lies sich er sich nicht mehr starten. Als ich es erhalten habe, stellte ich fest, dass das Netzteil nicht geleuchtet hat und auch keine Spannung raus kam. Daraufhin habe ich mir ein neues Netzteil bestellt, den Laptop angeschlossen und bemerkt dass es irgendwo raucht -> es war der Mosfet PQ502. Habe dann durchgemessen (siehe Thread) und stellte fest, dass PU501 von Pin 4 auf Pin 8 einen Kurzschluss hat, wodurch -höchstwahrscheinlich- der PQ502 durchgebrannt ist. Habe jetzt mal die Bauteile bestellt und werde berichten sobald ich sie eingebaut habe.

Greets, Grishnackh

[dellxps15]

Re: Alienware 17 (R5) shorted Mosfet

check why short happened too...... in many of pc with shorted circuit, when problem was not a capacitor but a mosfet, i got also bad gpu-cpu ram that caused the issue.

if u got short on cpu rail, check that cpu on some other laptop if u can.

this is just a suppose. could be easly possible that after mosfet replacement pc will work fine .

[tata123]

Re: Alienware 17 (R5) shorted Mosfet

Grishnackh, danke für die ausfürliche fehlerbschreibung....

yes most common shorts are on mosfet's or caps....