(Disclaimer, I consider myself an experienced "PC person", I work in the IT department at Fujitsu Siemens, but aside from an iphone this is my first experience with macs, so please bear with me if I'm overlooking something stupid ) A long while back I bought a 2nd hand Powermac G4 from ebay. It was running OS X 10.4.8 and didn't come with any install CD/DVDs. I upgraded the RAM from 2x128 to 2x256 which worked fine. Next however I tried to upgrade the hard disk from a 10GB IDE to a spare 40GB IDE I had laying around. Not having any OS X install media, I put both the 10GB and 40GB disks into a spare PC case, and booted from a Norton Ghost CD. I tried to clone the 10GB disk to the 40GB, but it complained that it couldn't do it due to the file system. Next I tried g4l which apparently doesn't concern itself with file systems and reads and writes raw data on the disk. This seemed to work OK, cloned the single partition on the 10GB disk to a new 10GB partition on the blank 40GB disk, with no errors. When I came to boot from the 40GB disk in the powermac though, I got the flashing question mark/folder screen. More worryingly the same thing happened when I put the 10GB disk back in. (I had tried all the various jumper settings on the two drives, replaced IDE cables etc etc, no difference) After that, following the advice on various forums I booted into Openfirmware and tried resetting the PRAM I believe, things like reset-all set-defaults etc etc, none of which made a difference. I've also tried holding down alt to bring up the "boot menu" but it didn't show any drives. The other night I took the powermac round to a friends who has an iBook G4. My plan was to put the iBook into target disk mode and install OS X from his iBook's DVD drive, using his original panther CDs and a tiger DVD. So we booted the powermac holding alt, c, d and all the other keys we thought were relevant (from here and various forums etc) but it wouldn't see any hard disks / DVD drives. We tried the other way around however, powermac in disk mode and installed panther from the iBook, onto the powerbook's hard disk over firewire. This worked and after the install the iBook booted from the powermac's hard disk. So we turned both machines off, disconnected the firewire cable, booted them both back up, the ibook booted to its hard disk running tiger, and my powermac threw up the same flashing ? folder icon.... The last thing we tried before we gave up for the night was booting the ibook into target disk mode, and booting the powermac holding alt. This time it does see the 40GB hard disk, and the hard disk and DVD drive in the iBook. Whichever one I select though, when I click next the screen flickers then comes back exactly the same, after about 20 seconds I can select another disk and try again, with the same looping result. So we're both stumped now. Back before I knew the guy with the iBook I was playing around in openfirmware trying to set the aliases for the hd and cd devices I think, so I've got a feeling I've done something in there. However I would have thought when I've done set-defaults reset-all etc this would have, well, reset everything? Does anyone have any ideas how I can get this thing to boot again? If you want devalias printenv etc etc outputs I can take photos of the screen. Thanks in advance for any advice!