Hi - I am looking for some information about the sort of things hard drives do when they fail, as I am having a tough time figuring out the problem with this one Quicksilver G4... There are two hard drives in this computer which occasionally don't mount at startup. However, they always pass diagnostics in Tech Tool Pro 4 and Disk Warrior. 1. Can this indicate that a hard drive on its way to failure? 2. Can an over-taxed power supply cause this (there are 5 internal hard drives)? 3. Can a quirky startup disk cause other devices not to mount - in other words, can a software problem cause this? The drives usually mount, but don't on occasion. I have swapped the cables, so that isn't the issue. I have reset the PRAM, NVRAM, power manager, etc. Any advice would be welcome! Thanks!