Dell 15R short circuit in io board

[rippergr]

Hello all,
I have a Dell 15R laptop which when I give it 19,5V in DG15 io board it short circuit.
I use a bench power supply and giving 19,5V it heat the mosfet PU301(mosfet in red circle in pictures). When I measure it with multimeter it seems ok.
If I give it less power (4v) in 1,2,3,4 pin I have ~2,5V .
In PD301,PC301 and PR310 I have the voltage that I give with power supply
I can't understand if the problem is that mosfet or another component.

[dellxps15]

Re: Dell 15R short circuit in io board

does it give short with multimeter? if u remove mosfet wich pins are shorted?

[polytek]

Re: Dell 15R short circuit in io board

check the ceramic cap

[peste]

Re: Dell 15R short circuit in io board

check without wifi card

[rippergr]

Re: Dell 15R short circuit in io board

check without wifi card

I already tried it this way and it's the same.

[rippergr]

Re: Dell 15R short circuit in io board

does it give short with multimeter? if u remove mosfet wich pins are shorted?

Pins 5-8 are short with ground 1-4 are not.
I haven't removed it from board I check the mosfet on circuit without power.

[rippergr]

Re: Dell 15R short circuit in io board

check the ceramic cap

This cap when I give 3V-4V it measures the same as the voltage I input.
How can I check it?

[dellxps15]

Re: Dell 15R short circuit in io board

remove pu301 and put 5 volt on pin 5. check if pc303 pc304 pc305 pc306 get hot and wich one.... just put 5 volt and see if any of them get hot, but however remove voltage after max 10-15 seconds; quickyer u check if any of them get hot better it is.

if none of them get hot, that voltage go to the connector. check big connector that goes to mainboard if pins 50,52,54,56,58 are ok

ps: from the picture try just to remove pc306 and check if still shorted. for me problem is this one (pc306 the one a bit bigger caps respect the other 3 smaller).
if this not solve short read up

[rippergr]

Re: Dell 15R short circuit in io board

remove pu301 and put 5 volt on pin 5. check if pc303 pc304 pc305 pc306 get hot and wich one.... just put 5 volt and see if any of them get hot, but however remove voltage after max 10-15 seconds; quickyer u check if any of them get hot better it is.

if none of them get hot, that voltage go to the connector. check big connector that goes to mainboard if pins 50,52,54,56,58 are ok

ps: from the picture try just to remove pc306 and check if still shorted. for me problem is this one (pc306 the one a bit bigger caps respect the other 3 smaller).
if this not solve short read up

I removed PC306 and the short is gone. I have 19,5V in pin 5-8 but only 3,5V to pins 1-4 is this normal?

[rippergr]

Re: Dell 15R short circuit in io board

UPDATE:
I tried to start the laptop without this capacitor and it starts fine.
Do I have to replace this capacitor or I can leave it without?

[dellxps15]

Re: Dell 15R short circuit in io board

replace it. check value of pr310 (240k) and pr3011 (47k)

[rippergr]

Re: Dell 15R short circuit in io board

replace it. check value of pr310 (240k) and pr3011 (47k)

Thanks for your help. Laptop has power and everythink is ok.