I have a computer here that doesn't want to boot up. When you turn on the power switch, the CPU fan and the power supply fan starts spinning but nothing else works. The optical mouse doesn't flick on, the monitor gets no signal, and the hard drive doesn't sound like it's working. What do you think the problem is? So far the things I've tried are: 1) hitting the computer case a few times, 2) yelling at it really loud, 3) taking the CMOS battery to see if that'll do anything.