I'd like to add a few more details here to help the diagnosis. After working with the Quadra for a few days, I've been observing some really erratic behavior. Usually what I get when I try turning it on is what I originally described - power lights come on, fans come on, hard drive spins up, but no startup chime and no video. Occasionally I'll get the startup chime but no video, or the crash chime. Last night I turned it on, actually got it to load the OS, and used it for about a half hour with no incident. I turned it off and went out, and the next time I tried to use it later on, I got nothing once again. Today I haven't had any better luck, but just a few minutes ago I tried running it, got a startup chime and video, but when I got to the "Welcome to Mac OS" screen, the system threw up a bomb dialog claiming there was an "address error." I don't know if this information will help narrow down the problem, but I thought I'd share it just in case. With all this taken into consideration, could it still be just the hard drive that's wrong with it? I have a new one coming in the mail, so I'll try it out when it gets here.