If you have a Compaq 1625 and get the beeps on startup and no video, this may solve your problem. Disconnect power and remove your battery. Hold down the power on button for about 29 seconds. Plug your power back in and restart the machine.
If you have problem getting power to your machine. I had the same problem. Everything work, but no power. Finally took everything apart and found that the female power connecter on the motherboard had separated from the motherboard. I had to soder a bare piece of wire from the female power plug to a point on the motherboard. Works fine now. When Compaq had a forum a while back, this seemed to be a source of trouble to folks, but Compaq (of course) said that this was not a problem.
Hope this helps someone.
Oh, why the 29 seconds, it may be less, but 29 somehow is stuck in my memory. Using the above method, I just restarted the video on my Compaq
Oh, again. This compaq is the worst buying decision I think I ever made.
wlk