K53SV in short circuit

[Learn2Day]

Hi guys,

I have a K53SV in hands and it's shorted in DC jack, i think it's not shorted in battery (only 4 pins grounded) but I'm unable to be sure without a schematic.
I already removed the jack to test and it's ok, but dunno where to test next.
I've attached some pics, the red components are shorted.

Hope someone can help, TIA.

[Learn2Day]

Re: K53SV in short circuit

Big mistake, laptop is a K53SJ, not SV, sorry.

[Learn2Day]

Re: K53SV in short circuit

Update:
I was finally able to charge the battery, and the laptop works fine on battery. The problem is definitely in the charger circuit.
PLEASE HELP!
Thanks.

[whaldsz]

Re: K53SV in short circuit

Did you pull the capacitors and tested them for shorts?

------ ignore this msg.

[Learn2Day]

Re: K53SV in short circuit

Well i was about to say which capacitors, when i payed attention to the ignore..

Still i'm fairly confused, i just pulled out the k53t schematics from another thread here and although the board is different the power circuit seems fairly similar. Problems are, part numbers are different, and i'm totally lost in where to test a physical shorted circuit between Vin and Gnd.
I see no component connected directly between Vin and Gnd at schematics charger input. Some help would be deeply appreciated.

Thanks.

[whaldsz]

Re: K53SV in short circuit

Test those capacitors then, also test the FET near those caps. Looks like this FET is connected to VIN through its SOURCE pin.

[Learn2Day]

Re: K53SV in short circuit

What caps? I think the red marked components are resistors, and according to the schematics i got from k53t they're not even there, just one 4k7 resistor.
The FET seems fine, although i can't test it with power it does pass my multimeter diode test from 5,6,7,8 to 1,2,3, and fails in reverse order. I think this proves conductivity is fine.

This all makes me feel more confident that the issue is within one or all of those 3 marked components, but.. I have no markings and no schematics telling me what they are. How am i supposed to replace this?

Thanks.

[Learn2Day]

Re: K53SV in short circuit

Update:

I removed all 3 marked red components and short is still there. PLEASE HELP!!!

[whaldsz]

Re: K53SV in short circuit

How many ohms is VIN to ground resistance?

[Learn2Day]

Re: K53SV in short circuit

It's physically shorted! 0 ohms, obviously.

[kc8adu]

Re: K53SV in short circuit

desolder the pjp points on the board and see if the short goes away.
divide and conquer.
look at the big trace that leads from the current sense resistor.thats the green one marked r020.
see the "pj" jumpers?

[Learn2Day]

Re: K53SV in short circuit

Hi guys,

I had to put this laptop on hold for a while and now I'm back at it.

The short is NOT in the DC Jack. I have tested this before. Removed PQ101 and R020 and short is still present, and BTW, there's no direct short from DC jack to PQ101 or R020.
I believe the short might not be located near the DJ jack, i also see alot of shorts near the battery pins. But without schematics I'm totally lost on my next step..

Any Ideas?

Thanks.

[Francisco.s]

Re: K53SV in short circuit

If you can get a regulated power supply, you can inject a few volts (2-3) limiting the current to less than 1 ampere, an check if a mosfet or capacitor gets hot.
Be extremely careful with voltage and current.
Good luck.