Troubleshoot peripheral connections
Peripheral connectivity issues create frequent support tickets and disrupt user productivity. Systematic troubleshooting of Bluetooth, Thunderbolt, and USB connections helps you resolve issues quickly and reduce repeat requests.
Mac peripherals connect through Bluetooth connections and Thunderbolt and USB ports. When connectivity issues occur, you can help users restore functionality by identifying connection methods, checking hardware compatibility, and following step-by-step solutions.
Bluetooth
Bluetooth is used to connect wireless devices like keyboards, mice, headphones, and printers to a Mac. If a Bluetooth device isn’t working, check whether Bluetooth is enabled (in Control Center or System Settings) and ensure that the device is discoverable and charged.
What to look for:
In the menu bar, the Bluetooth icon may be dimmed, spinning, or unresponsive.
When trying to connect or pair, these messages may appear:
Bluetooth Not Available
Unable to connect to device
Device not supported
Devices not appearing or not pairing
Steps to take:
Confirm the presence of the Bluetooth hardware. Click the Apple menu while holding the Option button, then choose System Information. Locate the Bluetooth hardware.
Turn Bluetooth settings off and on. On the Mac, choose Apple menu > System Settings > Bluetooth , then turn off, wait a few seconds, and turn on.
Confirm that the Bluetooth device has power
Restart Mac.
Unplug USB accessories. USB devices and hubs can interfere with Bluetooth. Disconnect them and test again.
Test in Safe Mode:
Shut down Mac completely.
Hold the Power button until “Loading startup options” appears.
Select the startup disk, then hold Shift and click Continue in Safe Mode.
When in Safe Mode, test Bluetooth. If Bluetooth works, something is interfering, like software or extensions.
Create a new user account and use it to test Bluetooth. This helps rule out account-specific settings.
Update macOS to the latest version.
Thunderbolt and USB
Thunderbolt and USB ports connect external storage, displays, input devices, and other peripherals. If a device isn’t recognized, first check the physical connection and try different ports or cables. The macOS app System Information utility can help verify whether the device is detected at a hardware level. For Thunderbolt-specific issues, ensure that firmware and macOS are up to date, and verify compatibility—especially when using adapters or docks. If you’re not sure what types of ports are on a Mac, see the Apple Support article Identify the ports on your Mac.
Try a different port. Mac computers often have multiple Thunderbolt/USB-C ports.
Restart in Safe Mode to rule out software conflicts. Hold the power button until startup options appear. Then select Startup Options, and start up in Safe Mode.
Check for macOS updates. Updates often fix compatibility and port issues.
Use Apple Diagnostics to test Mac. Apple Diagnostics may report hardware issues with the Thunderbolt or USB controller.
What to look for:
Thunderbolt or USB devices don’t mount or show any signs of power or activity.
System Information shows no connection. (If it’s empty or not detecting devices, the port or controller may not be working.)
Thunderbolt accessory can’t be used.
No display is connected.
Steps to take:
Try a different port. Mac computers often have multiple Thunderbolt or USB-C ports.
Restart in safe mode to rule out software conflicts. Hold the power button until startup options appear. Then select Startup Options, and startup in Safe Mode.
Check for macOS updates. Updates often fix compatibility and port issues.
Use Apple Diagnostics to test Mac. Apple Diagnostics may report hardware issues with the Thunderbolt or USB controller.