Problems with iMac G5 and bootup

First off, I have to say I'm not a Mac owner, not yet anyway. I wanted to buy one of the new iMacs, but lack of funds prevented that. A friend of mine at church told me she had an iMac that she was having problems with, and had to replace it. She said if I could get it working, I was welcome to keep it. So I have tried that a few times, and have spent a lot of time googling and looking around for answers, so I'm pretty close to saying "donate it to recycle place", but I thought I'd take a stab here first.

According to Apple's support site, it is listed as:

OBS,IMAC G5 (20-INCH ISIGHT)

Anyway, all I have with it is a keyboard & mouse, no other external anything. When you power it up, the light in the lower right comes on, and then after a minute or so, the fan gets going. Not having owned one, I can't tell if it's louder than it should be. But there are no other sounds. Once in awhile, (like maybe 1 out of 10 boot attempts), I get the Mac "chime" sound, but in all cases, nothing shows up on the screen - totally black.

I'm assuming the thing is likely fubared, without a couple hundred dollar repair. I've tried a few things I've read about, including unseating the ram (only one stick in there), and reseating it. Tried Option-Ctrl-P-R on reboot, and a couple other things of that nature. Nothing has worked.

From what I read, I'm likely out of luck, but I'm throwing this out there in case someone has some secret idea - a hail mary of sorts. Keep in mind I'm a total neophyte with iMacs, and "did you try" answers wil likely be met with "no", because I've never owned one before, and all the "usual" tricks are unknown to me.

Tkx.

P.S. I even tried booting it with NO RAM in there at all, figuring I'd get some sort of complaint about there being no ram. No luck there, either - it does the same as the other failed boot attempts. Not a good sign if the computer doesn't apparently notice that it has no ram in it at all! 🙂