Thunderbolt Accessory with iMac Error

Question

Thunderbolt Accessory with iMac Error

Has anyone figured out how to solve this error message:

"Cannot Use Thunderbolt Accessory

Connect accessory using a Thunderbolt capable cable."

This message came after my computer shut down with a power failure. Device is an external hard drive that is connected with a Thunderbolt 3 cable and had been working on the iMac for about 3 months.

Mac is a 2017 iMaC Retina, 5K running Monterey 12.2.1

Drive is a SanDisk Professional 1TB G-DRIVE PRO SSD using the included 40Gb/S Thunderbolt cable (which as noted was working in the past without this message).

I have tried unplugging the cable, replugging, restarting the computer...

iMac 27″ 5K, macOS 12.2

Posted on Mar 28, 2022 8:35 PM

Reply

Answer 1

Best reply

DiZoE

Level 4

2,937 points

Mar 28, 2022 9:06 PM in response to Macusedtobesoeasy

Hey there!

My first thought, considering it happened after an outage was to reset the SMC, the firmware involved with power management, so I think for your case, this maybe a quick and simple resolution, check it out:

How to reset the SMC of your Mac - Apple Support

If that doesn’t fix it:

Can you say it the same happens with other ports, if the same happens with other external drives, and finally if you are using any hubs or adapters?

Hope that helps!

Reply

Answer 2

DiZoE

Level 4

2,937 points

Mar 28, 2022 9:25 PM in response to geyoza

Sounds good, in that case I think the SMC reset may help. For your Mac, just:

Disconnect any external devices, shut it down, disconnect the power for 10 seconds, turn back on and re connect your external devices. Hope that’s all it takes!

Reply