Got a PowerMac G5 which fails to boot. I get the flashing folder w/ face and question mark. Reseted PRAM, no go. Tried Command+Alt+P+R, no go. So, I stuck in the 10.5 DVD and the machine gave me a message that it can't install (which is fine because I wasn't planning on reinstalling a newer OS/X anyways). I go into Disk Utility and I see no hard drives (only the optical). I drill down to SATA connections and I see nothing. I also tried plugging in a bootable fw external hard drive and it didn't pick it up. Dead mobo or dead hd or both?