Problem: hard drive cannot be detected

1. PCI bus out of specification, can cause problems
2. Power cable faulty or not plugged in
3. IDC cable in incorrectly or faulty CHECK BOTH ENDS
4. Master/Secondary conflict, disconnect all other devices on chain.
5. Check jumper settings. Some drives have a "single drive" setting, and won't work properly as a "slave" or "master" if they are the only drive in the chain.
6. As a last resort, ie.won't work at all after everything has been tried and warranty is no longer valid (not if it's a new HDD), try the freezer method (freeze the hdd in freezer then try again)