Bluetooth Problem in iMac

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I am having a problem with Bluetooth going off periodically so that I lose connection to keyboard and mouse. I can plug a wired keyboard in and a wireless (not Bluetooth) mouse, but these don't let me re-enable Bluetooth. The only way to re-establish a Bluetooth connection is to restart the iMac.

I have run Bluetooth "Debug" to reset the Bluetooth Module, performed SMC and PRAM resets but this hasn't made any difference. I also came across a suggestion that having "Hangover" enabled could cause Bluetooth issues, but disabling that made no difference either.

I am using a late 2015 21.5" iMac running macOS Mojave 10.14.3

Any suggestions for resolving this problem would be much appreciated.
 
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It may well be interference with the radio signals. BT uses frequencies also used by wireless home telephones, home automation, WiFi and other technologies. The first thing to look at is what changed right before the problem started. Have you added a wireless telephone, moved the WiFi router, added another BT device or wireless device in the vicinity of the system? If your home is near another, it might even be something THEY added to their home that is now interfering with your setup. Try moving things around just a bit, sometimes even just inches can make a difference.
 
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m.g.mcc
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Only thing that has changed is having an Android phone with WiFi enabled sitting close by. I will switch off its WiFi and move it away from the iMac to see if that makes any difference. Thanks for the reply.
 

Slydude

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Do you know whether your WiFi is using the 2.4 GHz band or the 5 GHz band? IIRC the 2.4 GHz band is the more likely band t be causing a problem. If that is the cause of the problem.
 

chscag

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My router sits about 3 feet from and above my iMac but even using the 2.4 Ghz band that close doesn't seem to affect BT. I usually keep the router set on the 5 Ghz band anyway just in case. I think that certain devices whether it be an iMac or MBP are more susceptible to interference than some others. It's difficult to sort out sometimes. But as Jake pointed out, a little bit of trial and error will go a long way to pinpoint it.
 
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It's just done it again, after waking from sleep. If I click on the icon in the menu bar it says "Bluetooth: Not Available". If I go into System Preferences, it says Bluetooth Off and the button to switch it on is greyed out. I suspect it is something more than interference and I haven't experienced a similar problem with a MacBook.
 
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Ah, new information. That symptom says that the hardware is failing. Either a connection, or a physical defect in the BT circuitry.
 
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Ah, new information. That symptom says that the hardware is failing. Either a connection, or a physical defect in the BT circuitry.

That's what I feared. Time to dig a Mac-Mini out of the cupboard again!
 
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Ah, new information. That symptom says that the hardware is failing. Either a connection, or a physical defect in the BT circuitry.

That's what I feared. Time to dig a Mac-Mini out of the cupboard again!


Have you tried any or all the Troubleshooting connection issues, or at least these suggestions:
https://www.macworld.co.uk/how-to/mac/fix-bluetooth-mac-3682642/

More hits for suggestions from here:
https://www.google.com/search?q=Mac...0l2j69i64l3.8054j0j7&sourceid=chrome&ie=UTF-8



- Patrick
======
 

chscag

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I believe the BT module sits on the same daughter board that holds the WiFi module. At least it does on many models. You can check to see if that's the same for your machine by going to ifixit.com. I would first try doing a SMC reset to see if that helps and brings BT back for you. I agree with Jake in that it may be related to hardware rather than interference.

BTW, changing out that board requires a major disassembly of your machine.
 

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