I have recently been building a functional MP5,1 (an upgraded 4,1) from a non-working rig I scooped up a few years ago which I have been tinkering with and throwing parts at until it eventually worked.
Since getting it working (after 2x Backplane replacements, and now a spare PSU and CPU tray), I've decked it out with a 6-core 3.46GHz CPU, 32GB of RAM, RX 580 8GB GPU, and a 1TB NVMe SSD. Monterey is installed via OCLP. Everything works great, except for WiFi which intermittently disconnects (always after sleep) and the internal stock Bluetooth module which is unrecognized in Monterey.
So, my latest addition to the build is a PCIe 1x WiFi/BT adapter which I ordered from China. I began on the path of getting things to work — the Bluetooth component in particular — and thought I'd take some photos and notes to share in a short photo journal in case this is of any use to someone reading.
I have a Late 2012 iMac 27-inch, which recently gave up the ghost, so repurposing the iMac's BCM94331CD Combo card was a no-brainer. It is Bluetooth 4.0 (LE), so some features (like Apple Watch unlocking) are not supported, but it was free and still an upgrade from the original '09 parts.
For the adapter, I considered either a mini-PCIe adapter card (that would fit into the existing Airport Extreme slot) or go the full hog and use a full height PCIe card. I turned to ChatGPT to ask which would be best and was directed toward the full size PCIe 1x card instead of the mini-PCIe style. According to ChatGPT, there are some limitations with this slot in the cMP:
I have seen many mini-PCIe WiFi/BT combo adapters floating around for the MP4,1 / 5,1 so I cannot confirm the above to be true, but I took the advice and went for the full height PCIe 1x card as directed — This also meant I could easily use external antennae.
Here's the card I ordered on the 'bay under the listing title:
"BCM94360CD BCM943602CDP WIFI WLAN Card to PCI-e 1x 16x Desktop PC WIFI Adapter"
Here I have installed the BCM94331CD Wifi/BT Combo card and connected the 4x antenna cables to the card.
Here's another angle showing the BT internal 4-pin USB connector at the right.
The card installed OK like this but I had some initial issues with the Wifi networks disappearing. I figured the "Legacy" support supplied by OCLP might be causing some issues, so I removed the previously installed Root Patches, rebooted and it started behaving as expected.
This is the existing stock BT module connected to the internal USB header on the backplane. As far as I can tell, it is of no use to macOS newer than Mojave. There is a short cable connecting the card to the backplane.
However, as seen up top in this photo, the supplied connector for the PCIe card is a standard internal USB 2.0 9-pin connection.
Shown here also is that small cable which connected the stock BT to the backplane. Note that pins 1 and 2 (lower side in the photo) on the left plug are routed to pins 2 and 3 (middle) on the right — we need to copy this across to the bigger USB connector.
I decided to keep it simple (and mostly reversible) by simply removing the BT module plug end (the flatter connector) and freeing the 4 pins. These are technically female pins, but their size is absolutely perfect for a snug fit into the 9-pin USB connector's sockets.
I found some product listings for adapter cables and this image confirmed the same pin crossover I noted earlier. Pins 1 and 2 on the Backplane/Motherboard side (at right) route to pins 2 and 3 on the Adapter side (left).
I also found a post from @tsialex which confirmed these findings:
So I fashioned this little adapter. The unused pins (3 and 4 on the smaller plug — left side in the photo) are routed into two of the blank pin sockets on the larger 9-pin connector just to get them safely out of the way and prevent a short. Note: the pins were pushed in firmly with the flat edge of a blade and require some gentle force to pull back out, so I don't think they are going to work themselves loose at any time.
Here is the adapted connection installed into position and mounted onto the backplane with a strip of Kapton tape.
The cable then routes behind the CPU cage and connects into the USB connector on the back of the PCIe card.
And the 4x Antennae provided are picking up a solid signal...
Once I booted back into Monterey, I could see Bluetooth was working, Airdrop from my iPhone was quick and easy, and Handoff started showing up in the Dock. But I was not able to get Universal Control to work out of the box as it looks like I need to spoof SMBIOS to an iMac18,3 or similar from OCLP to get this to work.
Since getting it working (after 2x Backplane replacements, and now a spare PSU and CPU tray), I've decked it out with a 6-core 3.46GHz CPU, 32GB of RAM, RX 580 8GB GPU, and a 1TB NVMe SSD. Monterey is installed via OCLP. Everything works great, except for WiFi which intermittently disconnects (always after sleep) and the internal stock Bluetooth module which is unrecognized in Monterey.
So, my latest addition to the build is a PCIe 1x WiFi/BT adapter which I ordered from China. I began on the path of getting things to work — the Bluetooth component in particular — and thought I'd take some photos and notes to share in a short photo journal in case this is of any use to someone reading.
Which WiFi/BT Combo card and adapter?
I have a Late 2012 iMac 27-inch, which recently gave up the ghost, so repurposing the iMac's BCM94331CD Combo card was a no-brainer. It is Bluetooth 4.0 (LE), so some features (like Apple Watch unlocking) are not supported, but it was free and still an upgrade from the original '09 parts.For the adapter, I considered either a mini-PCIe adapter card (that would fit into the existing Airport Extreme slot) or go the full hog and use a full height PCIe card. I turned to ChatGPT to ask which would be best and was directed toward the full size PCIe 1x card instead of the mini-PCIe style. According to ChatGPT, there are some limitations with this slot in the cMP:
I have seen many mini-PCIe WiFi/BT combo adapters floating around for the MP4,1 / 5,1 so I cannot confirm the above to be true, but I took the advice and went for the full height PCIe 1x card as directed — This also meant I could easily use external antennae.
Here's the card I ordered on the 'bay under the listing title:
"BCM94360CD BCM943602CDP WIFI WLAN Card to PCI-e 1x 16x Desktop PC WIFI Adapter"
Here I have installed the BCM94331CD Wifi/BT Combo card and connected the 4x antenna cables to the card.
Here's another angle showing the BT internal 4-pin USB connector at the right.
The card installed OK like this but I had some initial issues with the Wifi networks disappearing. I figured the "Legacy" support supplied by OCLP might be causing some issues, so I removed the previously installed Root Patches, rebooted and it started behaving as expected.
The next step was to get Bluetooth working.
This is the existing stock BT module connected to the internal USB header on the backplane. As far as I can tell, it is of no use to macOS newer than Mojave. There is a short cable connecting the card to the backplane.
However, as seen up top in this photo, the supplied connector for the PCIe card is a standard internal USB 2.0 9-pin connection.
Shown here also is that small cable which connected the stock BT to the backplane. Note that pins 1 and 2 (lower side in the photo) on the left plug are routed to pins 2 and 3 (middle) on the right — we need to copy this across to the bigger USB connector.
I decided to keep it simple (and mostly reversible) by simply removing the BT module plug end (the flatter connector) and freeing the 4 pins. These are technically female pins, but their size is absolutely perfect for a snug fit into the 9-pin USB connector's sockets.
I found some product listings for adapter cables and this image confirmed the same pin crossover I noted earlier. Pins 1 and 2 on the Backplane/Motherboard side (at right) route to pins 2 and 3 on the Adapter side (left).
I also found a post from @tsialex which confirmed these findings:
So I fashioned this little adapter. The unused pins (3 and 4 on the smaller plug — left side in the photo) are routed into two of the blank pin sockets on the larger 9-pin connector just to get them safely out of the way and prevent a short. Note: the pins were pushed in firmly with the flat edge of a blade and require some gentle force to pull back out, so I don't think they are going to work themselves loose at any time.
Here is the adapted connection installed into position and mounted onto the backplane with a strip of Kapton tape.
The cable then routes behind the CPU cage and connects into the USB connector on the back of the PCIe card.
And the 4x Antennae provided are picking up a solid signal...
I will leave that for another day, unless there are other workarounds for UC?