I've got an old Power Mac G4 Cube I'm trying to get working. So far I've installed both 10.3 and 10.4. Both have installed successfully, but will not boot from the installed system. The system shows the Apple logo then briefly shows the blue screen, but before the login screen shows the screen goes back to grey (usually with a mouse cursor) and the system just stops. No extreme fan noise (though being a Cube, there isn't really a fan to make noise).
I've cloned a 10.4 install DVD to a hard drive partition and booted successfully from that, so I'm guessing the hard drive is (relatively) fine. Verbose mode will complete successfully, so the crash(?) seems to be in the login system. I can start up into single-user mode but am not sure how to go about things from there.
So yeah, either a problem with the setup assistant or with the login system, but no idea what could be causing it. Any help?