USB Drive works attached to keyboard but not to iMac!

[Stevebarnett99]

This is driving me mad. I have a late 2012 iMac 27" running 10.10.3 and a Sandisk UltraII mounted in a Dynamode 2.5" USB3 carrier formatted for MAC OS Extended (Journaled). It works perfectly if I plug into the left hand end of the wired keyboard but is not recognised if I plug into the USB ports on the back of the iMac.

I have tried turning off - removing power lead and restarting then plugging all the USBs back in but its still not recognised or even visible.

Suggestions please.

 

[Fishrrman]

Do you have access to a DIFFERENT Mac, just to try the drive with another Mac to see if it mounts?

Having said that, my advice is to go with "what works".
That is to say, if you need to plug the drive into the keyboard port in order for it to be seen, that's what you gotta do...

The "long way around fix" might be to copy everything you need from the problem drive to another drive. Then connect it to the Mac and re-initialize HFS+ with journaling enabled. Will it mount properly after doing that?

 

[Stevebarnett99]

plugged into iMac 21" mid 2011 running 10.9.5 worked straight away, then plugged into Macbook Air mid 2012 10.10.2 and it failed to see it at all.

I tried the same drive in a different enclosure and it works consistently - incompatibilty between the firmwares no doubt but damned annoying as I drove 2hrs into Cambridge just to get the enclosure....

But why does it work with the keyboard and not the iMac direct? I guess it moves the incompatibility one step away. I wonder if it would work with a small USB hub as intermediary.

 

[ColdCase]

The keyboard may be USB2 and the enclosure negotiates USB2 protocol when attached to the keyboard, which is a simple but slow protocal that just about anything works with. When directly attached to a computer, it negotiates USB3. USB3 is much more complicated and enclosure vendors rarely get it right. USB3 is just flakey, sometimes you get lucky.

Dunno, just guessing.

You could try a different cable.