Laptop turns off 30 seconds after boot up


May 26, 2011
Hello Everyone and thanks in advance for the help.
Compaq Presario V5000.
It apparently had some kind of virus and was taken to best buy for a diag.
Unit has hardware issues related to ram, optical drive, and possibly motherboard. Shuts off during windows and cannot pass memtest. Disc drive ejects during install.

I have replaced the memory with a 1gb stick that I know is good. Same Problem.
I took the laptop apart and inspected the MB for soldering that has come loose and cleaned the heatsink/fan. Same Problem.

It seems like the computer will turn on and run for anywhere between 30 seconds and 5 minutes then it just shuts off. There is no OS that I know of on the computer and I cannot get the XP disc to run long enough to even do a repair. When I start up the computer as normal it says NTLDR is missing.

Just wondering if you guys have any other ideas that I could try to get this thing to stay on so I can reinstall windows.
Thanks again.