Sometimes when I power up my 5215CD, it makes a very loud beep (almost sounds like a siren going off), but it only happens if the computer has been idle (not used) for a long period of time, or if it wasn't shut down correctly.

I'm not sure why it does this, but my suspicion is a faulty chip on the motherboard, or possibly (although I really doubt this) capacitors. If I ever catch it, I'll record it, and post it on Youtube.