First post here but a longtime Computer Technician.
I've found a complete workaround for the cMP 4,1 and cMP 5,1 machines no longer accessing Bluetooth after installing Ventura.
This is going to be more complicated to write about than the actual install. I am a Photographer who uses my classic Mac Pro 5,1 machines daily for Photo Editing but also a retired US Navy Data Systems Technician. I know my stuff when it comes to researching.
🙂 I am not associated with any of the sellers or manufacturers referred to here. I reference some links that I am also not associated with. This is provided only for reference and I am not responsible if you damage your computer, lose any data, etc...
Remove the wifi and bluetooth cards completely from the cMP. The instructions for doing this are available with a google search online.
crystalidea.com
has some reference material about removing the bluetooth and WiFi modules.
We will not be reinstalling the stock modules. Period. *Ignore the rest of the tutorial other than removing the modules.*
Insulate the antenna cables with electrical tape to prevent shorts to the motherboard.
Install a FENVI FV-T919 PCI-E Wireless Adapter. Use the included cable with the FV-T919 plus an adapter cable from standard PC Motherboard USB header pins to USB A to connect to a USB 2.0 or USB 3.0 port for Bluetooth. I ran the adapter cable out of a blank card slot and plugged it into an external USB port. Others have successfully run it to an internal USB A port on a PCI-E USB 2.0 or 3.0 card.
I pieced this together from other posts here plus a lot of research online. The FENVI FV-T919 uses an Apple brand controller so it is natively supported without any drivers required. It supports Continuity, Handoff, AirDrop and Bluetooth 4.0, etc.
I did have to do a clean install of Ventura to get the WiFi working as it continuously searched for WiFi when I tried to run it on my system that I had upgraded from Monterey to Ventura. After the clean install it works very well. I also bought external antennas to test out as I had read that there were some issues with the included antennas not providing strong enough signals. Your mileage may vary but I have tried both the original and the external sets of antennas with good luck. I have this setup running now on my 4,1 -> 5,1 machine. Please note that I have all firmware updates current on the Mac and it has 64GB RAM, 3.46 GHz 6-Core 5690 XEON, etc.
It is working so well that I'm doing the same install on my main workstation 5,1 Dual Processor with 5690 3.46 GHz processors and 128GB RAM.
I found the needed parts on Amazon and had the system up and running again in a day.
I personally chose these parts based on my own research and can vouch that they work well for my particular installation. Once again, your milage may vary.
I hope these images are self explanatory but you will need to order 2 sets of the external antennas as the FENVI FV-T919 card has 4 antennas ports on it.
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