Thunderbolt Issues

[mmkerc]

I have an M1 mini with a Belkin Thunderbolt 3 and an OWC Thunderbolt 3 hub, and dual dell 32" QHD monitor and other stuff. All peripherals attached to the OWC hub quit working with the exception of the display. I restarted and the display dropped off. i.e. Only the display and peripherals that's connected to the Belkin hub worked. I unplugged and replugged the thunderbolt cable at the OWC hub and the display comes on but not the other peripherals. I am going to swap the cable out to see if that is the issue. Any other ideas to determine if it is the OWC hub, or the port on the mini?

 

[chabig]

Don’t change anything but the hub. Keep the same port, cable, and peripherals. Try each hub. Does one work and one not? Then move to the other port and repeat. If one hub is broken it should become apparent.

 

[mmkerc]

Point of clarity on your suggestion. Are you saying swap the thunderbolt cables from the mini to the hubs or are you saying leave the TB to hubs cables and swap which hub the peripherals connected to each hub?

I am fairly certain the issue is one of three possibilities:
1. The TB port on mini has gone bad
2. The TB cable connecting the OWC hub to the mini has gone bad
3. The OWC hub has gone bad.

The Belkin is working fine, as is all peripherals connected to it.

PS all of this system has work flawlessly since December

 

[chabig]

I’m suggesting that you can only make one change at a time while you are troubleshooting.

To find out whether a port on your Mini is bad, keep the working hub, cables, and peripherals the same and simply move the Thunderbolt cable to the other port. If one hub works on both ports then the port is working.

To check the cable to the OWC hub, keep everything the same and swap in the cable from the Belkin hub. If one cable works and one doesn’t you’ll learn which one is bad.

If both ports and both cables seem to work, pick on port and one cable and keep them unchanged while you swap in each hub. If one hub is bad, you’ll find out.

 

[joevt]

Check the Thunderbolt tab in System Information.app. Make sure you see the docks. Make sure both docks are connected using "40 Gbps x1" "link width x2".

You have one display connected to HDMI port of M1 Mac mini? Because you cannot connect two displays via Thunderbolt.