I have a G4 466 digital audio with a 30 GB drive, and within the past couple of weeks it has begun to emit a high-pitched whine. It's not that loud, but I can definitely notice it. The pitch stays the same, but the loudness sometimes fluctuates.
I know it's the hard drive because the noise stops when the disk spins down. The rest of the computer seems to be running fine; no system problems that I've found. I'm just concerned that something is going wrong with my drive.
The computer is only a little over two years old, hopefully the drive is ok. I believe it's a maxtor, but I'm not sure. It's whatever came with the computer as I ordered it from apple.
I have backed up my data just in case, but this would be a bad time to have to re-installl everything.
Top