Just pulled out an old computer while my other one is down for the count, but I can't get it to work. It has been sitting up for a while, but the last time I used it it was fine. Now when I turn it on it will go right back off then start itself back up and make 3 beeps, one short and two long ones. Nothing comes up on my monitor, but the computer will stay on after that. I searched around and a few people say that I might have to leave it running for a while so it can do something about the BIOS losing settings or memory of something, but I left it on for hours and nothing happened. Any suggestions?