MP 5,1 loses BT dongle connection whenever I switch startup disk

[MacSince1985]

I use a Broadcom bluetooth dongle for my Magic Mouse since the MP's built-in bluetooth is too weak.

I'm in the slow process of configuring a clean Mojave install on a NVMe drive to replace my primary Sierra install. This is my work computer, so I do this in my spare time (hence the slow process). And since Sierra does not recognize NVMe, I have to boot from a third drive in High Sierra before I can boot from Mojave on the NVMe drive.

To summarize:
• Sierra on Apricorn Velocity Duo SSD Raid = current main startup drive
• High Sierra on HDD = interim drive to recognize NVMe
• Mojave on NVMe SSD = future main startup drive

My problem is that whenever I switch startup drive, the mouse becomes unresponsive and I have to play with Bluetooth Explorer and reboot multiple times to get the dongle recognized again, especially when switching from Mojave back to Sierra. I suspect some BT info is updated in NVRAM when I boot in Mojave. Any suggestion on how to smooth this transition?

 

[PianoPro]

I use a Broadcom bluetooth dongle for my Magic Mouse since the MP's built-in bluetooth is too weak.

I'm in the slow process of configuring a clean Mojave install on a NVMe drive to replace my primary Sierra install. This is my work computer, so I do this in my spare time (hence the slow process). And since Sierra does not recognize NVMe, I have to boot from a third drive in High Sierra before I can boot from Mojave on the NVMe drive.

To summarize:
• Sierra on Apricorn Velocity Duo SSD Raid = current main startup drive
• High Sierra on HDD = interim drive to recognize NVMe
• Mojave on NVMe SSD = future main startup drive

My problem is that whenever I switch startup drive, the mouse becomes unresponsive and I have to play with Bluetooth Explorer and reboot multiple times to get the dongle recognized again, especially when switching from Mojave back to Sierra. I suspect some BT info is updated in NVRAM when I boot in Mojave. Any suggestion on how to smooth this transition?

Have you manually loaded the same BT link keys into each version of Mac OS? If not each Mac OS version will have a different BT link key and you will be constantly re-pairing when switching OS's.

 

[Macschrauber]

Pull the cable of the internal bluetooth board. I did so and have less trouble with my bt dongle on a 5.1

 

[PianoPro]

Pull the cable of the internal bluetooth board. I did so and have less trouble with my bt dongle on a 5.1

That's a lot of trouble and not necessary if you set up the BT dongle correctly.

 

[crjackson2134]

Have you manually loaded the same BT link keys into each version of Mac OS? If not each Mac OS version will have a different BT link key and you will be constantly re-pairing when switching OS's.

How is this done? I have the same issue as OP using the genuine Apple BT cards.

 

[PianoPro]

How is this done? I have the same issue as OP using the genuine Apple BT cards.

I'll write up the exact procedure from my notes late tonight when I have some time. I've never posted it before so I don't want to get any of the commands wrong doing it from memory. It only takes a couple of minutes to implement, but other instructions that I've found on the internet are wrong (use old file names for Mac OS's prior to HS and Mojave).

Do you also use BT Mouse with Windows? I can also write up that process, which is just a bit more involved because the BT link key has to be reformatted for Windows. But then you can switch freely between Windows and Mac OS's without ever re-pairing.

 

[crjackson2134]

Do you also use BT Mouse with Windows?

I do, but it works fine. Switching between win/macOS causes no problems.

 

[PianoPro]

I do, but it works fine. Switching between win/macOS causes no problems.

Interesting. I haven't experienced that working well without copying the Magic Mouse Bluetooth Link Key from Mac OS to Win 10. Perhaps that is something taken care of automatically by installing the Bootcamp drivers, but I don't recall that.

Objective: Use the Magic Mouse with multiple Mac OS's without having to re-pair when switching Mac OS volumes.

Solution: Pair the Magic Mouse ONCE with one Mac OS, and then copy that Mac OS volume's Bluetooth (BT) Link Keys to other Mac OS volumes.

In Mojave and High Sierra the BT Link Keys are stored in:
/private/var/root/Library/Preferences/com.apple.bluetoothd.plist
(The Link Keys were stored in a different plist prior to High Sierra)


Example step-by-step process to copy the com.apple.bluetoothd.plist from High Sierra to Mojave using the terminal:

1) Pair the Magic Mouse in High Sierra if it is not already paired.
2) Copy the High Sierra com.apple.bluetoothd.plist to the desktop using the Terminal:

cd Desktop
sudo -s (Makes you #root so proceed carefully)
cp /private/var/root/Library/Preferences/com.apple.bluetoothd.plist .
(don’t forget the spaces and the . at the end of the command)​

3) Boot into Mojave with a wired USB mouse (do NOT re-pair the Magic Mouse in Mojave).
4) Make a backup copy of the Mojave com.apple.bluetoothd.plist from the Terminal for safety:

cd Desktop
sudo -s (Makes you #root so proceed carefully)
cp /private/var/root/Library/Preferences/com.apple.bluetoothd.plist .
(don’t forget the spaces and the . at the end of the command)

Use the Finder to add .backup to the end of the plist file now on the Mojave desktop.​

5) Use the Finder to copy (drag) the com.apple.bluetoothd.plist file on the High Sierra desktop to the Mojave desktop.

6) Copy the High Sierra com.apple.bluetoothd.plist file into the Mojave OS

if not still #root from above:
cd Desktop
sudo –s (Makes you #root so proceed carefully)

cp com.apple.bluetoothd.plist /private/var/root/Library/Preferences/com.apple.bluetoothd.plist​

7) Restart Mojave and the Magic Mouse should be paired


Windows 10:

The procedure to copy the Mac OS BT Link Keys to Win 10 is a bit more involved, but not hard to do. I can provide it here if requested. Note: The Magic Mouse should be paired at least once with Win 10 using its standard process before executing the above Mac OS procedure, else the Mac OS procedure above will have to be repeated again if you later do the Win 10 procedure.

 

[MacSince1985]

I disconnected the built-in BT and it helps a bit. The dongle is recognized with all OS versions, but the mouse requires re-pairing each time I switch OS version.

Since the MP needed a good cleaning anyway, disconnecting the module did not add much time.

(The Link Keys were stored in a different plist prior to High Sierra)

Where are the link keys stored in Sierra? I suspect I would have to edit the plist instead of simply copying it.

 

[PianoPro]

Where are the link keys stored in Sierra? I suspect I would have to edit the plist instead of simply copying it.

I think in Sierra they are at /private/var/root/Library/Preferences/blued.plist

I don't know if that file is compatible with HS or Mojave, but I guess I would just try renaming it to com.apple.bluetoothd.plist and copying it into HS or Mojave per my post above before trying to edit the plist. It might work.