Logic Pro 9 and GarageBand '11 won't recognize MIDI controllers

Question

Hi there,
I have two MIDI controllers that are not getting picked up by Logic or Garage Band and I'm unable to figure out why. I'm running Mac OS 10.9.4 (Mavericks) on a Mac Mini with a 250 GB SSD and 4 GB of RAM.
Setup 1 is a simple Acorn Masterkey 49 USB controller whose manufacturer claims needs no drivers, although it doesn't show up in my Audio/MIDI setup pane at all, no matter how many times I restart the computer and/or the controller in any combination. I can't use it with Logic or with Garage Band.
Setup 2 is a Digi002 Rack connected to the Mac Mini by Firewire and connected to an old-school Korg M1 as a MIDI controller. I can launch and hear the tracks I've made in the past with Logic, but now that Korg M1 is invisible even though the Core Audio Manager says my Digi002 Rack is connected and running. This setup has really never been able to speak with Garage Band, although I have been able to connect it successfully in the past.
I'm a newbie to this and don't know how to get under the hood to fine-tune MIDI set-ups within Logic or GarageBand. Is there something funky going on between Logic 9 and Mavericks, however? I'm beginning to wonder if that's the issue.
With thanks,
Dustin.

Answer 1

Hi Dustin,
Nice to see someone pose a complete question with all the details...
First thing to do would be to delete Logic's preferences and the control surface preferences. Although I don't think it's going to help. I'll post the method at the end of this post.
One of the problem with older MIDI devices is that Apple changed something in their MIDI spec and some older MIDI devices either don't work (not recognized) or if they are recognized don't work reliably. Another problem, depending on ho old your Mac Mini is, the newer machines have USB 3.0 ports and that poses another hurdle.
Here's two things to try for the Acorn.
Turn the computer off, unplug the Acorn's USB cable. Restart the MacMini and let it settle for a couple of minutes, open Audio-MIDI Setup... plug the Acorn in, see if there's and life.
Try a powered USB 2.0 USB Hub, a hub that has it's own power supply. If you don't have one maybe you can borrow one as it's only a -possible- solution.
The Problem with the M! and Digi002 may be related. Are you using the very latest drivers available for the 002? Again, this may be a MIDI compatibility problem, although I thought this was USB only, I suspect it's more of a Digi002 driver issue with Mavericks than anything else.
MIDI Out on the M1 to MIDI IN on the 002
Delete the Logic 9 preferences file and control surfaces file.
In the Finder, choose Go > Go to Folder from the menu.
Type ~/Library/Preferences in the "Go to the folder" field.
Press the Go button.
Remove the  com.apple.logic.pro.plist file from the Preferences folder. Note that if you have programmed any custom key commands, this will reset them to the defaults. You may wish to export your custom key command as a preset before performing this step. See the Logic Pro User Manual for details on how to do this.
If you are having trouble with a control surface in Logic Pro. then delete the com.apple.logic.pro.cs file from the preferences folder.
Be sure to include the Tilde~ in the path name above, be sure and delete both files.