imac white screen of death

[Wman]

So I've been given an iMac that may or may not be fixable.
It's a 20" white flat panel iMac (not sure if intel or late g5). I don't know how to identify exactly what model it is if I can't even boot it, which makes fixing the problem even more difficult. When I boot, I get the chime and sometimes i get the questionmark folder but usually just a white screen and some slight beeping noises.
I've tried resetting PRAM (holding cmnd+opt+P+R on startup) and it reboots, but there is no difference
I've tried booting and holding power, I get a loud, long beep and a restart, but again nothing
I've tried power down+ take off cables, wait 15 seconds, plug back in and it automatically restarts, but to no avail
I've tried booting off an old OSX 10.4 Tiger DVD, and the DVD drive makes some sound but no boot. I've also got a bootloader i made for another computer that might help that I can boot off of.
Anyways, can any of you offer me advice as to how to fix/identify/anythign else this iMac, as I'd really like to get it working soon? I only hope the logic board's not fried.
-thanks!

 

[Wman]

in general, does this sound like a hardware or software problem? I'm kind of relying on fixing this mac to make money to pay my next rent check. If it is a hardware problem, would it be something I can do like replacing hard drives, ram, etc, or a ****** job like replacing the logic board? IF this is somethign I can fix easily without having to open the machine it would be awesome.
so if theres any info i can give any of you to help me fix this probllem, please tell me, thx.

 

[chscag]

When you have an iMac to repair, chances are it has to be opened and that's always a challenge. It sounds like the hard drive failed and is preventing the machine from booting.

One way to test is to open up the iMac and remove the hard drive. Then use the original startup DVD to run the Apple Hardware Tests.

To learn how to open the iMac go to iFixit: The free repair manual and look up the procedure for changing out the hard drive in that model.