Hello: My G4 TI P/B is an 867GHZ , 15 inch. The retail Panther install disk is v10.3, (3). The retail Leopard Install disk is v10.5.4 and the box it came with states the requirements are an Intel, PowerPC G5, or PowerPC G4 867. After the screen pixel problem, the P/B was started-up on T/D/M so the hard drive could be checked from my Mac Pro (S/L} using Tech Tool, it said that the disk was corrupt and to repair, the Repair stated that the disk would not dismount, even tho the icon disappears from the PRO desktop, it is not accepted. I suspect all the failed attempts might have triggered the disk corruption. Regards John