16-inch MacBook Pro Bluetooth issue

Guys please contact Apple support if you have this issue and clearly explain how this issue appeared after connecting an external bluetooth receiver. This might be solvable with a software update. The workaround with an old BT 2.0 which seems to work for some people and while cleverly found cannot be the real solution.

If no-one tells Apple about this issue, they don't know about it or how many people are affected (which is important for determining priority) how can we expect them to solve it?

Fixed with this dongle! https://www.ebay.com/itm/Wireless-Adapter-USB-2-0-1-0-For-Keyboard-Mouse-For-Bluetooth-V2-0-EDR-Receiver/143337681457?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649

The one I received is not the mushroom looking one shown in the picture. It says CSR 4.0 on it, but it's really BT 2.0 with a broadcom chipset (BCM2046B1). Worked first try, no problem.

Isn't it clear that lots of people *are* contacting Apple support and visiting Apple facilities with this issue – but the support personnel are either clueless, or coached to appear clueless & non-committal, despite being pointed to this thread?

Hasn't this thread – on an official Apple support site! – been alive for 11 months now? (There are similar threads about this issue on Reddit, MacRumors, YouTube, etc.)

Doesn't it show a 100% reproducible flaw in Apple's high-end laptops, that any Apple engineer could reproduce instantly with a $9 BT 4.0 dongle?

Doesn't this thread point the way to a fix – something triggered in the firmware by those old dongles, in a certain pattern – that an Apple Bluetooth engineer could easily understand, then simulate with an OS/firmware update?

Is it really possible a $2 trillion company doesn't already have a tracking issue with an accurate description for this flaw?

No, they must have simply decided to deprioritize its fix, because the lost functionality & hours of time of those affected are less salient than the staff costs to fix.

So by all means, insist on warranty returns/replacements or motherboard swaps, so Apple faces some cost for inaction. But let's not portray this as the victims' fault for not letting Apple know about the problem. Apple's been told, repeatedly, worldwide.

I have reported, as have countless people here, as Gordon Mohr points out.

I have been unable to contact Apple itself, only representatives but I have given feedback also on Apple's Feedback portal (posted somewhere around this thread quite a few times) and I don't really want/can take my laptop to a repair center (not to mention there isn't an official one in Portugal as, apart from the website, Apple doesn't really operate here).

I have went ahead on a leap of faith and purchased another BT pen (https://www.ebay.es/itm/Mini-Adaptador-USB-V2-0-EDR-Bluetooth-Dongle-compatible-Windows-XP-Vista-7-8-10/280638333155?hash=item41575920e3:g:9JEAAOSwsD1btgTx) and it's still going to take at least one week before it gets here)

I'll report my results once I can

Posting on this forum won’t get Apple engineers attention as I think this is only meant for users helping each other. By the activity in this thread we can say that this is at least a common issue. But we cannot be sure this is reproducible on all laptops of these model ranges. So I think it would really help if people having this issue contact Apple support: https://getsupport.apple.com and clearly explain how this issue appeared after an external Bluetooth receiver was connected.

I did that and by their instructions I collected some diagnostics data their engineers can examine. The more people to that, the more information they’ll have to diagnose the bug. It will become clearer to them how many people are affected.

Also don’t forget their support employees probably mostly get questions such as people who don’t know how to pair their mouse and it might be rare they actually come across real hardware or software bugs. Or if it’s a hardware problem it’s usually the one laptop that needs to be fixed with a replacement part and not a design flaw in all laptops of the model. That’s probably really rare. So having some patience, clearly explain how this issue appeared and let them go through their procedures to eliminate other causes is good. I found the advisors I chatted with or spoke by phone very professional and helpful.

Anyway, my support case is escalated and they will contact me later this week. I really hope this can be solved in a software update.

I wish it was that simple, because it seems like not every 2.0 device will do it.. Mine, for instance, doesn't.

A couple posts back I posted my device version/id and that one causes the issue, but seems like it doesn't solve it. I'd be happy to lend it to someone to investigate if they want, but I wouldn't recommend it.

I still have the issue and have tried the whole process multiple times, so it looks like there's something more to it and others have also said so.

I'm waiting on a couple other dongles I bought in the meantime to try and solve this. Feels like wasted money but at least both of them were under 12€ total, shipping included.

Just to give an update, I managed to get my hands on a "Matrix Bluetooth USB mini (version 2.0, Class 2)" (it's one the ones that have the mushroom head) and following AntiHawk's procedure the fix worked.

I will try to break it again and retry my old BT adapter to reproduce the issue and see if I can capture any logs

I can also confirm the AntiHawk solution. For those looking for a compatible 2.1 Bluetooth Dongle for the fix, I can confirm that this one from Argos worked a treat, £10.....

https://www.argos.co.uk/product/8365448?clickSR=slp:term:micro%2010m%20usb%20bluetooth:10:20:2

Apple, how can you be allowing motherboard replacements for this? Whilst unorthodox, there is a solution. Why have you not provided a patch?

I also was caught out when accidentally connected a hub with bluetooth dongle already connected. Luckily, I was able to find this thread, otherwise, it would have been an expensive, seemingly pointless, and time consuming repair. It's not very environmentally responsible.

Thank you poxin. I followed in your footsteps and it worked. If this success lasts, I will be very happy. The key is getting the correct adapter, without which the procedures are frustrating and seemingly useless.

Is there a Broadcom pattern?

One BT5.0 with Broadcom on the MacBook Pro 16".

One BT 4.0 dongle with Cambridge Silicon Radio broke my MacBook.

That one and another BT 4.0 dongle with Cambridge Silicon Radio did not work with all my devices.

Two BT 2.0 dongles with Cambridge Silicon Radio did not fix the original problem.

One BT 2.0 dongle with Broadcom fixed the problem.

I wonder if Cambridge Silicon Radio is better at breaking (a dongle broke my Mac), incomplete at functioning (two dongles and ineffective at fixing (two dongles were useless), and Broadcom is better at fixing the Broadcom Mac. That's my experience after owning 5 dongles.

As of macOS Catalina update 10.15.7 (19H15) I am now unable to brick the bluetooth with CSR 4 bluetooth dongle on my MacBook Pro (16-inch, 2019).

While I do not recommend testing this, it might be possible that Apple has implemented a patch to fix this problem.

If you want to test if bluetooth is actually fixed by patch issued by Apple please have the CSR 2.0 dongle available just in case as I did :)

The Bluetooth Preferences panel still crashes sometimes when CSR 4 dongle is unplugged but rebooting the Mac fixed all 10 attempts to brick the bluetooth.

Sometimes even turning bluetooth off and on again fixed the bluetooth after unplugging the CSR 4 dongle.

PS.

The rabbit hole still deepens in my case as I was able to fix intermittient WI-FI disconnection problems by causing kernel panic with excessive CSR 4 dongle re-inserts x'D

Well that looked very promising and thanks for sharing. I ran these commands but it doesn't fix my internal bluetooth. I even bought the external bluetooth 2.0 "mushroom" receiver but that doesn't work for me either.

Getting fed up with this and almost ready to bring this thing back to the store, if they accept it..

What does system report say for bluetooth component (what is the Manufacturer set to)? Before I issued commands listed above, manufacturer ID was set to Cambridge Silicon Radio, even though external dongle was not plugged in. Now, it is set to this:

 Handoff Supported:	Yes
 Instant Hot Spot Supported:	Yes
 Manufacturer:	Broadcom
 Transport:	UART
 Chipset:	4364B3
 Firmware Version:	v50 c4178
 Bluetooth Power:	On

Also, it may be a long shot, but you could try running extra commands to explicitly remove the controller switch behaviour and internal controller info (though it seems that those should be deleted when 'sudo nvram -c' command is invoked):

sudo nvram -d bluetoothHostControllerSwitchBehavior
sudo nvram -d bluetoothInternalControllerInfo
sudo nvram -c
sudo reboot

  Handoff Supported:	Yes
  Instant Hot Spot Supported:	Yes
  Manufacturer:	Broadcom
  Transport:	UART
  Chipset:	4364B3
  Firmware Version:	v50 c4177
  Bluetooth Power:	On

Interesting that your firmware version is slightly higher.

Under USB in system info my external receiver was always listed as bluetooth device even when not attached but that is now gone since a week or so. But internal bluetooth is still not working. Also running the other commands you listed didn't help.

Funnily the external receiver that caused all this actually works now if I connect it, it didn't do anything useful before. Seems something might indeed have changed in the last software update, but not a full fix for me at least.

If you read `nvram` manual, you'll notice that there is an option to set firmware variables from a file, namely, the -f option. Would be interesting to try to import from a known good configuration (that maybe someone else could export)

% nvram --help
nvram: (usage: no such option as --)
nvram [-x] [-p] [-f filename] [-d name] [-c] name[=value] ...
-x use XML format for printing or reading variables
(must appear before -p or -f)
-p print all firmware variables
-f set firmware variables from a text file
-d delete the named variable
-c delete all variables
name=value set named variable
name print variable
Note that arguments and options are executed in order.

Personally, it was another huge pain in the ***, but I completely cleaned the mac and went back to Mojave.

Still have the -3903 log entry on Bluetooth Explorer though, but everything thing else is as normal as it can be

I would avoid exporting everything, nvram contents could contain some sensitive information that should not be shared. That being said, I could export bluetoothInternalControllerInfo, but again, it could make things even worse, as it seems that you guys could have a different firmware version, which might not support some of my settings...