Thanks guys. Once I knew what I was looking for, I realized the problem. There's supposed to be a little plastic thing that goes over the power button (as shown in this picture - http://www.vectronicsappleworld.com/collection/articlepics/pm720075/snap32.jpg). Pretty sure I saw the broken pieces...
I haven't used a Mac in over 20 years, so assume I know absolutely nothing. And to prove how little I know, they may be the most nubie question ever:
Just bought a Power Mac 7500/100 off ebay (for next to nothing.) The seller didn't do a decent job of packing. There was obviously some damage to...