A friend of mine has a Compaq Presario v3000 laptop that is 2-3 years old. About a week ago she reported it wouldn't boot when the pwr button was pressed, no lights, no screen, no POST, no nothing. I got my hands on it and removed the HD to get some files off it, assuming it was in fact dead. After I got her the files she needed I put the drive in and tried to boot just for laughs. It worked fine. I ran AV/malware scanners/Hijack this and didn't find anything critical. I rebooted 24+ times with and without the battery with no problems. The power cord has good contact and while the battery isn't new it holds about 45 minutes of charge and operates fine within that limit. Thinking all was well I gave it back to her. A week later she reported the same thing. I had her remove the battery and power cord, plug them back in and it booted right up and has continued to work for the past couple of days. Any ideas what could be causing this? It appears power related rather than a problem with Windows or the HD, but I'm not sure what to try next to track down the cause.
It is using a 3rd party ac adapter, but it has been for more than a year with out a problem. I put a voltage meter on the adapter and it's within spec. When the condition occurs and it wont boot, the power socket LED is lit up, indicating AC power and the ac adapter itself has a green LED. I originally thought it might be a loose AC jack, but I see no evidence of that. While running, I jimmied the adapter plug around and saw no loss of power. When I pulled the plug, Windows switched to battery and switched back when plugged back in.