There are four 500 MHz iMac G3s in my Journalism class at school, three with 10.2.8 installed and one with 9.2.1, but they all seem to have the same problem: after the display has been off for awhile (though the computer itself is still on), it won't turn back on until I restart the computer. It isn't an issue when the displays are off for a little while--I can't be any more specific than this, as I've never timed it or anything--but the computers are pretty much on all the time, and in the mornings, after being on all night with the screens off, I have to use the restart button on the back.
It's fine if it's a hardware problem because we're going to buy/get a hold of a lot of new ones; I just need to know if we need to replace these four or not.
EDIT: Also note that they never go into sleep mode. I'll ask this before trying, since it'd be great if I didn't have to talk to the Tech Admin (would need an administrative account): would putting them to sleep after, say, an hour solve it? Or at least might it?