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Ted L. Nancy · Sep 1, 2008, 10:12 AM

I took the factory-installed 320 GB HD out of my Mac Pro and dumped it into an external eSATA/USB case for use as a SuperDuper! backup for my MacBook Pro.

It squeals. I've run diagnostics, nothing seems to be wrong with the drive. Currently, it is positioned vertically, sometimes moving it makes a difference initially, but then it reverts back to the squealing. When I try to access the drive from OS X, the squealing subsists. My enclosure does not have any fans. It sits behind my MBP (about 4-6 inches away). My 20" external screen is nearby and so is my wireless laser mouse.

I never noticed any squealing while in the Mac Pro.. then again it was inside a much larger box, which I happen to keep in a desk compartment for tower computers, and it was also around the Pro's fans which could have drowned out the squeal.

Thoughts? Suggestions?

seanc · Sep 1, 2008, 12:21 PM

What brand is this external case? I'd suspect it may be a component of interface board that's squealing.

Ted L. Nancy · Sep 1, 2008, 01:36 PM

Originally Posted by seanc

What brand is this external case?

http://www.cooldrives.com/esata-usb-...removable.html

seanc · Sep 1, 2008, 01:45 PM

I take it you have it hooked up via USB?

It's not exactly a cheap enclosure, but that can't rule out the interface boards. I can only suggest you pick up a cheap enclosure and give that a try to see if the squeal stops, that would rule out the drive/enclosure either way. If it continues, we can look at other factors.

Ted L. Nancy · Sep 1, 2008, 04:48 PM

It is hooked up via eSATA with an Express Card adapter...

Ted L. Nancy · Sep 14, 2008, 02:08 PM

UPDATE: I haven't gotten a "cheap enclosure" to test with yet, but I did get really fed-up with the squealing and unmounted the HD in OSX this morning.

While unmounted (but with the enclosure still plugged in and on) the drive STILL squeals? Does this help rule out anything?

seanc · Sep 14, 2008, 03:09 PM

That depends on whether the drive spins down when you unmount it or not. If it span down, the drive is ruled out.

Ted L. Nancy · Sep 14, 2008, 03:11 PM

How would I know if the drive spins down when I unmount it?

seanc · Sep 14, 2008, 03:14 PM

Plug it into the computer so it mounts, then put your ear on it and unmount it. If you hear a click and the whirring slow down, the drive has spun down.

Ted L. Nancy · Sep 14, 2008, 03:21 PM

Gotacha, thanks. I just followed your directions, and I don't think it spun (spins) down. However, when the drive was unplugged from my computer, I turned it back on, and I don't think it "spun up." (So, could it be that the enclosure does not have the dive spin down when unmounted, but if turned on without being connected to a computer, it doesn't spin up the drive?)

I'm gonna leave it in its current state (turned on having not been plugged into my computer) for a while and see if the noise occurs...

seanc · Sep 14, 2008, 03:28 PM

It would be strange for it not to spin down the drive. I take note when I'm using 2.5" and it does spin down but haven't paid attention when I'm using 3.5" drives, I'll test one tomorrow for you, bear in mind this is a cheap enclosure that we use to rescue dying drives but it should do.