How do I fix Bluetooth connection issue on my iMac?

Bluetooth completely drops out for no apparent reason, and at random times. I lose keyboard, trackpad and mouse and the only way I can find to get it back is to Restart the computer. It tends to happen mostly when more than one user is logged-in, and mainly becomes apparent when the computer will not Wake Up as usual on mouse/trackpad activation. However, it's just happened while I was in the middle of doing something. (Another user was logged-in.)


The only way I've found to re-boot is to plug in the keyboard and then use Fn+ Ctrl+F2 to get to the Apple menu, scroll down to restart using arrows and then hit enter.


If anyone has any ideas how to just reboot or repair the Bluetooth side of things, it'd be much appreciated


[Re-Titled by Moderator]

Original Title: Sudden loss of bluetooth connection

iMac (2017 – 2020)

Posted on Jun 21, 2025 8:23 AM

Reply
Question marked as Top-ranking reply

Posted on Jun 21, 2025 10:43 AM

Hi,

To fix Bluetooth connection issues on your iMac, start by restarting both your iMac and the Bluetooth device. If that doesn't work, try resetting the Bluetooth module, unpairing and re-pairing the device, or checking for wireless interference. You can also try updating your macOS and ensuring your device is in pairing mode. 


Here's a more detailed breakdown of troubleshooting steps:


1. Basic Troubleshooting:

  • Restart your iMac: A simple restart can resolve many temporary glitches. 
  • Restart the Bluetooth device: Turn the Bluetooth device off and then back on. 
  • Toggle Bluetooth off and on: Go to System Settings > Bluetooth and turn it off, then back on. 

2. Resetting the Bluetooth Module:

  • Option-Shift click the Bluetooth icon: Hold down the Option and Shift keys while clicking the Bluetooth icon in the menu bar.
  • Select "Reset the Bluetooth module": From the Debug menu, choose "Reset the Bluetooth module".
  • Restart your Mac: After resetting, restart your iMac. 

3. Unpairing and Re-pairing:

  • Forget the device:
  • Go to System Settings > Bluetooth, find the device, and click the "i" icon, then select "Forget This Device". 
  • Re-pair the device:
  • Put the Bluetooth device into pairing mode and follow the on-screen instructions to pair it again. 

4. Checking for Interference:

  • Move devices: Ensure your iMac and Bluetooth devices are within a reasonable distance of each other and away from potential sources of interference like Wi-Fi routers or microwave ovens. 


5. Advanced Troubleshooting:

  • Update macOS:
  • Make sure your macOS is up to date, as updates often include Bluetooth improvements. 
  • Reset SMC/PRAM:
  • If the issue persists, you can try resetting the System Management Controller (SMC) and Parameter RAM (PRAM) to refresh hardware settings. 
  • Delete PLIST files:
  • In some cases, corrupted Bluetooth preference files (PLIST files) can cause issues. You can try deleting these files and restarting your Mac. 

6. Terminal Command:

  • Open Terminal:
  • You can use the Terminal to reset the Bluetooth module. Search for "Terminal" in Spotlight.
  • Enter the command:
  • Type sudo pkill bluetoothd and press Enter. You may need to enter your administrator password. 

If none of these steps work, it's recommended to contact Apple Support or a certified technician for further assistance. 



Similar questions

6 replies
Question marked as Top-ranking reply

Jun 21, 2025 10:43 AM in response to jfromplymouth

Hi,

To fix Bluetooth connection issues on your iMac, start by restarting both your iMac and the Bluetooth device. If that doesn't work, try resetting the Bluetooth module, unpairing and re-pairing the device, or checking for wireless interference. You can also try updating your macOS and ensuring your device is in pairing mode. 


Here's a more detailed breakdown of troubleshooting steps:


1. Basic Troubleshooting:

  • Restart your iMac: A simple restart can resolve many temporary glitches. 
  • Restart the Bluetooth device: Turn the Bluetooth device off and then back on. 
  • Toggle Bluetooth off and on: Go to System Settings > Bluetooth and turn it off, then back on. 

2. Resetting the Bluetooth Module:

  • Option-Shift click the Bluetooth icon: Hold down the Option and Shift keys while clicking the Bluetooth icon in the menu bar.
  • Select "Reset the Bluetooth module": From the Debug menu, choose "Reset the Bluetooth module".
  • Restart your Mac: After resetting, restart your iMac. 

3. Unpairing and Re-pairing:

  • Forget the device:
  • Go to System Settings > Bluetooth, find the device, and click the "i" icon, then select "Forget This Device". 
  • Re-pair the device:
  • Put the Bluetooth device into pairing mode and follow the on-screen instructions to pair it again. 

4. Checking for Interference:

  • Move devices: Ensure your iMac and Bluetooth devices are within a reasonable distance of each other and away from potential sources of interference like Wi-Fi routers or microwave ovens. 


5. Advanced Troubleshooting:

  • Update macOS:
  • Make sure your macOS is up to date, as updates often include Bluetooth improvements. 
  • Reset SMC/PRAM:
  • If the issue persists, you can try resetting the System Management Controller (SMC) and Parameter RAM (PRAM) to refresh hardware settings. 
  • Delete PLIST files:
  • In some cases, corrupted Bluetooth preference files (PLIST files) can cause issues. You can try deleting these files and restarting your Mac. 

6. Terminal Command:

  • Open Terminal:
  • You can use the Terminal to reset the Bluetooth module. Search for "Terminal" in Spotlight.
  • Enter the command:
  • Type sudo pkill bluetoothd and press Enter. You may need to enter your administrator password. 

If none of these steps work, it's recommended to contact Apple Support or a certified technician for further assistance. 



Jul 1, 2025 2:06 PM in response to jfromplymouth

The following will require any USB keyboard and mouse. If you don’t have them, borrow or buy them, they are inexpensive!


1.     Connect the USB keyboard and mouse to the computer.

2.     Open System Preferences – Bluetooth

3.     Un-pair the wireless keyboard and mouse.

4.     Turn off Bluetooth

5.     Restart the computer in Safe Mode per the directions in Start up your Mac in safe mode - Apple Support

6.     Restart the computer normally.

7.     Open System Preferences – Bluetooth

8.     Turn on Bluetooth

9.     Re-Pair the wireless keyboard and mouse.

10.  Unplug the USB keyboard and mouse and begin testing the wireless devices again. 


Jul 1, 2025 4:53 AM in response to kaz-k

Thanks very much, however many of your solutions rather rely on being able to "click," which I am unable to do as the mouse & trackpad have - at this stage - lost connectivity! So ... any ideas on keyboard shortcuts, please, to achieve the same results? I should add, that Ctrl+F8 does not seem to work to get me to the status menus, so being able to turn Bluetooth on and off is not even possible with that method. But, many thanks once again.


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How do I fix Bluetooth connection issue on my iMac?

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