Hard Drive will not open

[gfclef]

1 G Mac G4, 1.75G Memory Mirror -Door
OS 10.4.11

I have 3 Hard drives installed and just recently I've lost access to one of them.
I made it my Start-up drive for a week before switching to another - when I tried to go back and open it that's when the trouble started.
If I start my computer and hold down the "Option" key, I can choose which Hard Drive to use. This particular Hard Drive will give me a continual "Spinning Ball" and never open. How can I open it???

If this is something that I can correct, then I would want to do that. If not, as a last resort, I will take it in for repair. I have tried to start it in Safe Mode, but it will not work. It won't advance past the spinning ball.I have tried the Repair Disk Utility got error message - "Repairing disk failed with error Could not unmount disk"
Error message with "Verify Disk" - "Verify volume failed with error Could not unmount disk"

thanks,
gfclef

 

[rubaiyat]

I presume the Hard Drive is installed internally.

Firstly try physically disconnecting the Hard Drive by shutting down your Mac and removing the HD cable. Then reboot with it disconnected. Shut down the Mac again.

Reconnect the Hard Drive and see if you can access it with Disk Utility, DiskWarrior or TechTool Pro whilst booted from another Hard Drive.

If you can:

1. Run Disk Utility 1st, verifying and repairing. There is a "S.M.A.R.T." option which will check if there is a physical drive problem.

2. Run DiskWarrior.

3. If neither of those rectify the problem, try TechTool Pro with check media [this will take a long time].

This should resolve whether it is a software or hardware problem.

If it is a software problem and unresolveable, you may just have to cut your losses and reformat. If it is hardware it usually means getting a replacement drive under warranty as recovery options are very expensive and usually not worth it.