I have a 1st gen Mac Pro (MacPro1,1) with 4 internal drives:
- Bay 1 - 500GB - OS X
- Bay 2 - 500GB - Windows 7
- Bay 3 - 1TB - Data
- Bay 4 - 1TB - Data
All drives are Western Digital Caviar Black, if that matters.
For a while now, bays 3 & 4 have been flaky with recognizing the drives at all within the system. 6 months ago, I had trouble getting bay 3 to work. Now, bay 4 is having the problem. I know it's not the drive because I can swap the drives & whatever's in bay 3 will work. When the system is booted, I look through /dev to see how many disks are listed, and it's only 3.
I've tried multiple things such as resetting the SMC controller & zapping the PRAM, neither of which work. Due to the randomness of the problem & the fact that 6 months ago, it was bay 3 that was having this problem, I'm starting to think it's related to the power supply or the logic board but I'm not 100% certain.
I bought this used, so I don't have the original DVD disks that came with it, so I can't run the Apple Diagnostics. I'd appreciate any ideas.