External HDD Not Showing Up

[gamerish]

I have a 500GB Seagate FreeAgent GoFlex External HDD that I've been using without problem on my 2012 Macbook Pro Retina. I'm selling the Retina and loaded all my files and apps onto the HDD without issue. But when I plugged it into the laptop I'll be using in the meantime (a Core 2 Duo 2010 Macbook Pro), it didn't show up in Finder. The indicator light was on and I could her it whirring away, but it never showed up. So I plugged it back into the Retina and it wasn't showing up there either (even though it had been just fine a couple minutes ago). Then I plugged it into a PC laptop I have on hand and it worked just fine.

What gives?

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And literally the second I pressed the "Post Thread" button, it showed up.

smh

 

[Mr. Retrofire]

I have a 500GB Seagate FreeAgent GoFlex External HDD that I've been using without problem on my 2012 Macbook Pro Retina. I'm selling the Retina and loaded all my files and apps onto the HDD without issue. But when I plugged it into the laptop I'll be using in the meantime (a Core 2 Duo 2010 Macbook Pro), it didn't show up in Finder. The indicator light was on and I could her it whirring away, but it never showed up. So I plugged it back into the Retina and it wasn't showing up there either (even though it had been just fine a couple minutes ago). Then I plugged it into a PC laptop I have on hand and it worked just fine.
...
And literally the second I pressed the "Post Thread" button, it showed up.

Sounds like a defective file system or partition info. If you use HFS+, then the fsck_hfs tool checks the file system, before the system allows read/write access to the volume. This can take a long time.

Check the fsck_hfs.log in the Console.app.

It is also possible that the power supply dies in the next days. Let us hope it is just a temporary issue with the file system.

 

[Fishrrman]

"What gives?"

Important Question:
Is the drive "bus powered" only, or does it have its own power supply?

If it's a bus powered drive, it's _possible_ that the drive isn't getting enough power (when connected to the older MacBook) to fully spin up and mount.

If the drive also has an external power supply, try using that.

More questions:
What is the partition map used on the drive?
How is the drive initialized (Mac HFS+, or something else)?

 

[cocacolakid]

I'd move/copy the important stuff off of it ASAP just to be safe. Hopefully it's only a USB bus problem as others mentioned.