Green iMac DV won't turn on

My Dad has a green iMac DV that won't turn on. The green light comes on, and it makes the noise that it turned on, but the screen stays black and the computer doesn't make noise like it's running.

Is there a fix? Is it cheap, or should we think about buying a new computer? He's had it since 2000. He'd like to keep it and use it.

Most everyone around here except me and a few others will tell you to dump it.
I say put a new Pram Battery in it and see if it starts up. If it want you my have to dump it as other bad things like a back loop transformer gone bad can cause the same thing. You have to take the bottom off and the silver shield to get to the battery. Go luck.

Thanks duder. We turned it off and on and it seemed to work again. We'll replace the battery when we get the chance. Know of a good place to get the battery?

The battery is a 1/2 AA 3.6 volts. I buy mine off ebay. Its the same battery used in alarm systems. You can also look here.Find the latest Performance Upgrades, Firewire and USB Hard Drives, SATA, Memory, Laptop Battery, and more at OWC

You can also pick up those batteries at Radio Shack (or Maplin in the UK)