Thunderbolt Connection Issues & Troubleshooting

This article addresses inquiries regarding UAD-2 Thunderbolt devices that won’t connect to your computer. The vast majority of these cases can often be narrowed down to a bad Thunderbolt cable.

Note: This article addresses Thunderbolt 2, 3 and 4 issues and troubleshooting steps.


  • The UAD Meter & Control Panel displays the message No Devices Found even though your device is powered on and connected.
  • You touch the Thunderbolt cable and a beeping sound comes out the speakers followed by the No Devices Found message.
  • Your host computer shuts down the moment you connect your Thunderbolt cable.
  • Your host computer randomly restarts or shuts down on its own without a visible cause.
  • You get UAD error codes such as -38, -51 etc in your DAW environment.
  • Unexplained CPU spikes in your DAW software.
  • You get the spinning wheel of death when hovering your cursor over the UAD Meter & Control Panel.
  • You see a Connecting to Apollo message when you thought you were already connected.
  • You experience sluggish behavior on your host computer.


Check the cable is properly plugged in

  1. The first step is to unplug the device, wait a few seconds, then reseat the cable firmly into the port.
  2. If that did not solve the issue, try using a different Thunderbolt port.
  3. Test the cable with another Thunderbolt device.
  4. PRAM / NVRAM Resets and SMC Resets may also help resolve issues with Thunderbolt UAD-2 devices not being recognized by Apple computers.
  5. If the issue is not resolved by then, a replacement cable may be necessary.

Important Note: All of these symptoms can also occur with a brand new cable right out of the box.  A cable being "brand new" does not mean it isn’t faulty.

All Thunderbolt cables certified by Intel as Thunderbolt compliant are compatible with Thunderbolt-equipped UAD-2 / Apollo devices. This includes the standard coaxial Thunderbolt cables like those offered through Apple & Apple Stores, as well as optical Thunderbolt cables like those made by Corning


Check Cable Type and Thunderbolt Cable Orientation (Thunderbolt 2 only)

Make sure that the cable you purchase is not a Mini-Display cable.  Your cable should have the Thunderbolt logo on it (that looks like a combination of a lightning bolt and an arrow pointing down).

When connecting UAD-2 Satellite Thunderbolt 2 to the computer, always check the orientation of the Thunderbolt 2 cable. The Thunderbolt logo must be face up on the Thunderbolt 2 cable when plugged into both the Satellite and the computer - if the Thunderbolt logo is not face up then the cable is inserted upside-down, which can be done fairly easily. 

Note: On iMac computers, the Thunderbolt logo on the Thunderbolt cable should face left (when looking at the back of the iMac).

Likewise, make sure that your computer actually has a Thunderbolt 2 port, and not the identically shaped Mini-display port.  The port should have the Apple Thunderbolt logo on it, which looks like a combination of a lightning bolt and an arrow pointing down.

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