Mac Mini G4 problems (usb devices/gray screen)

[CrashPL]

Greetings macos9lives crew!
I recently picked up a G4 Mac Mini (1.42 GHz) model, with MorphOS installed on the hard drive. Since I was really tempted to try out the Mac Mini 9.2.2 v9, I decided to clean the Mini a bit, remove the hard drive and format it on another Mac, and finally burn the CD with the OS.

Sadly, everything went downhill from there - after putting everything together, for some reason the Mac Mini stays on the solid gray screen for around 3 minutes, and them immediately starts flashing the question mark folder - it doesn't even attempt to boot the CD. What's worse, I also found out that the USB keyboard and mouse doesn't work, so I can't even eject the CD, zap the PRAM or boot into Open Firmware (when I ran the previous installation of MorphOS, the mouse and keyboard worked just fine, so no idea what happened there...)

Any idea how to make it work? Will an official USB Mac keyboard and mouse from the era solve the issue?

[IIO]

probably a leftover from morphos.

i know nothing about it, but i´d say you should try to reset OF as well as PRAM, then try again to boot from CD or boot manager.