Question : Problem: Compaq Presario Won't Boot or Power Down properly

I took in a customer's Compaq Presario 900 laptop today with a bad DC Jack. I disassembled the unit with no problems what-so-ever. I replaced the DC Jack and now when I power up the unit (doesn't matter if it's the battery or the AC Adapter power), the CPU fan and the rear case fan spin up, but nothing else.

I'm not getting any video internal or external.

The only way I can power the unit down is by disconnecting all power sources.

Any help would be appreciated.

Answer : Problem: Compaq Presario Won't Boot or Power Down properly

Remove cmos battery now (for few minutes)  to reset system see if it works. This is first of all I would do. I know disassembly the laptop is not easy, but good to open again and recheck everything.

Sometime, customer is not telling us everything, so I suggest hook up the drive on other system and check it.

Regarding remove cmos battery before soldering, I think we should.