Power Mac G4 cannot load any os past 9.0

We have a power mac g4 dual 450mhz with 256mb of ram that runs os 9.0 just fine. When you try to install any other os from CD the g4 shuts itself off. When you install another os from withing os 9.0 the install goes fine until you hit restart the g4 starts to boot up then shuts itself off. We have tried different ram, harddrive reset and probably stuff that I have forgotten. We think it may be a bios problem but we cannot find a bios update for os 9.0 or 9.1. Any help getting this thing up to os X will be greatly appreciated.

have you updated your firmware?

Possibly some incompatible 3rd party hardware?

ed724

Wanna buy my PowerMac G4?
500 mhz
512 megs of RAM
Upgradeable to 2 gigs.
4 mb L2 cache.
80 gig HD.
And it has Mac OS X 4.10 preloaded.
Included iLife 08,Flash 8, Dreamweaver 8,Macromedia Suite,Adobe Creative Suite 2 which includes Photoshop and everything else. Toast 8, iChat, Automator etc. Also has Candybar paid for to customize the dock and icons.

PM me if you're interested.