My Maxtor OneTouch 4 is not consistently showing up on my Explorer window -- sometimes it is only there for a few minutes and it is then immediately gone. Do these flake out when they have been powered on for too long?? I cannot figure this one out to save my soul. The light, in front of the unit sometimes blinks, and sometimes stays continuously on. Any help would be appreciated.
External hard drives are certainly less reliable than internal ones on account of the circuit board inside the enclosure which converts the drive's native interface to USB.
These boards often fail, rendering the drive unusable, but the drive itself is still okay.
If that's what's happened in your case, you need to crack open the enclosure (don't bother looking for screws, there aren't any), disconnect the drive from the converter board, remove it and fit the drive either internally or buy a third-party enclosure for it.
My Maxtor OneTouch 4 became 'flakey' two years ago, but in my case it was the actual drive that had failed, a fact I discovered by testing it with "Seagate SeaTools for Windows". If you want to test yours, click "Downloads" on this page: http://www.seagate.com/support/downloads/seatools/