IndiaReFix - Laptop & TV Repair Forum

M/B: QUANTA AX1
MODEL: COMPAQ CQ42
PROBLEM: DEAD

This mb came dead. No light on dc jack.
3v, 5v rails present
no short to ground anywhere.
sensing voltage at battery connector & power switch present

after much effort found that SIO kb3926QF D2 was faulty as pin no 90(DNBSWON#1) should have 3.3 volt but was giving only 1.45 volt. This signal originates from kbc.

Replaced kbc. Now ok

This signal (DNBSWON#1)comes after pressing the power button.your lap is dead .please correct me if I'm wrong

Dear Samanthban, This is what i do mean also. After pressing power switch DNBSWON SHOULD BE 3.3V BUT WAS GIVING 1.45V.Yeh laptop was dead.

Thanks for replying some what you did is correct learnt one thing thanks .I used to go for S4/S5 command .