Dell 1558 short to ground

[jbstokyo]

Trying to refresh my knowledge on board level troubleshooting.. I've been out for more or less a couple of decades from repairing laptops and such. Need extra info on any usual or particular components that might also be affected.

im trying to revive a dell 1558 (DAFM9CMB8C0).. Shorted whenever you plug in the adaptor.

Mosfet PQ24 and PQ25 is both gone.. replaced.. but still shorted to ground. I have check some resistor and caps to no avail. my next step would be replacing Max8731 charging IC.

Any addition info or usual components that i should also check that might be the culprit? thank you in advance.

[imranromi]

Re: Dell 1558 short to ground

When plug in charger gone off or not?
What short 3v/5v/19v.

[raajkumar]

Re: Dell 1558 short to ground

Check all Caps on 19V Line. Check at VCC core GFX Core Mosfet Also.

[jbstokyo]

Re: Dell 1558 short to ground

When you plug in the charger or power supply.. voltage drop from 19v to 2v.. mosfet on vcc core over heats so i replaced both.. (si4835d). Still waiting for my order of max8731... i will check other mosfet on vcc and gfx core as well.. thank you.

[emmanuelbill1988]

Re: Dell 1558 short to ground

please you have to check all the caps on 19v line or you can post schematic here

[jbstokyo]

Re: Dell 1558 short to ground

Ive replaced a shorted cap, mosfet and max8731 on the 19v rail.. +5v/3.3 alw is now ok... but now the problem is the 1.8v... rt9024pe +5v input is ok but there isnt any 1.8v output.. hoping this is the last bad component.

Any replacement fot RT9024PE?

[jbstokyo]

Re: Dell 1558 short to ground

Got the unit workin.. thanks everyone for your inputs.. cheers

[raajkumar]

Re: Dell 1558 short to ground

Good try. Keep it up.