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I have a 500 GB Maxtor external USB hard drive.

Normally it works fine.

But about once a week when I turn on the computer (laptop), it shows up as an unformatted hard drive.

When I double-click on the drive symbol, I get a message asking me if I want to format it.

When this happens, I've learned to unplug the USB, then plug it back in, the unplug and plug it back in about 5 more times until it finally shows up correctly with all its data (265 GB are used).

And then it works fine until the next time that I turn on the computer and it displays itself as an "unformatted drive" and I go through the same procedure.

Has anyone else experienced this? What could be the problem?

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up vote 4 down vote accepted

I had an Calvary external hard drive that did the same thing. I got sick of it and popped it open and put it in a new enclosure and it worked fine. I think it was a problematic SATA to USB bridge, because I've not had the problem at all since.

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this sounds likely. if OP's enclosure is new and under warranty, he should consider returning it for replacement. (don't return the drive, just the enclosure!) – quack quixote Oct 18 '09 at 20:39
Good point on the warranty. I tend to just eat it so I didn't think of that. If they won't RMA the enclosure separately, he could copy the files off, dban the drive and get it replaced. Otherwise, decent enclosures don't cost much. – emgee Oct 18 '09 at 20:56
@quack @emgee what do you mean by "taking off the enclosure", my maxtor drive looks like this… and the only way I can image getting into it is prying it open with a butter knife which I'm sure would void any warranty on it, etc. how do you "pop it open" as you describe? – Edward Tanguay Oct 18 '09 at 21:00
If you bought the drive as a unit, you'll need to return the whole thing. Quack was assuming you had purchased a drive and a drive enclosure separately. – CarlF Oct 18 '09 at 21:41
If you can copy the data off of the drive and get it replaced, you may want to do so. Otherwise, yes, you'd probably need to pry and/or break it open to get the drive out. And yes, that would definitely void the warranty. But voiding the warranty and may be better than the alternative -- getting a new, blank hard drive for free. – emgee Oct 18 '09 at 22:13

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