Dell Inspiron 5521 wont power up with charger

[sonunigam]

Hello all,

I'm working on a Dell Inspiron which is not powering up with charger, but when i connect the battery the laptop working fine. But when i see battery meter on taskbar the message shows, (Plugged in, Charging). But actually it is not storing or saving the charging in battery.
I've changed Battery charging IC PU100 (ISL88731CHRTZ). But the problem is still same.
The Laptop motherboard model is Compal LA-9101P. Can anyone tell me what should i check?
I'll appreciate the help.
Thanks.

[samanthban]

Re: Dell Inspiron 5521 wont power up with charger

when you connect dc jack pr 102 should be 18-19v

[sonunigam]

Re: Dell Inspiron 5521 wont power up with charger

No Voltages on PR 102. . . Any suggestion? how to make voltages there?

[BlueMidnight]

Re: Dell Inspiron 5521 wont power up with charger

Disconnect the battery and plug in the charger. Start following the voltage..

1) Check for 19V at connector PJPDC and on both sides of fuse PL901.
2) Check both sides (pins 1-3 and 5-8) of input MOSFETs PQ100 and PQ101. If voltage doesn't get through PQ100, then it's bad.

If voltage gets through PQ100 but not PQ101...
3) Measure gate voltage on pin 4 of PQ101. Around 8V means the MOSFET should be on, so it is bad. 19V means it is being told to stay off, so try to investigate why that is. If in doubt, measure voltages on all pins of PQ103, PQ104, PQ109, PQ113, PQ114, PQ1111 and post them here.

EDIT: Also, check for a short to ground. With multimeter in diode mode, put red on ground and black on PR102. Reading of < 100mV is a short.

[sonunigam]

Re: Dell Inspiron 5521 wont power up with charger

Hello Bluemidnight,
Thanks for your help it was PQ101 PNP Mosfet bad. I just change it and the laptop working fine now. Thanks a lot dear.
I appreciate your help. Can you give me your whatsapp?

[sonunigam]

Re: Dell Inspiron 5521 wont power up with charger

Hello Bluemidnight,
The Voltages on Gate pin of PQ101 was high like 19V. Is it okay or terrible thing?

[BlueMidnight]

Re: Dell Inspiron 5521 wont power up with charger

For P-Channel MOSFETs... a high gate voltage = off, and a low gate voltage = on (for N-Channel MOSFETs it is the opposite). Either is perfectly normal as long as it is off when it is supposed to be off and on when it is supposed to be on.

PQ101 should be turned on when running from AC and turned off when running from the battery (or if a problem is detected and the motherboard forces it off).

[HarryPK]

Re: Dell Inspiron 5521 wont power up with charger

nice