WiFi and Bluetooth stopped working. After replacing the WiFi cable, the bluetooth started working again but WiFi still not working

Question

The WiFi on my MacBook Pro Unibody Mid 2012 15'' stopped working a few weeks ago and shows "Wi-Fi: no hardware installed". After searching online, I found this post here MacBook is displaying the message "no hardware installed" when I click on Wi-Fi and here Bluetooth and wifi stopped working

Now, here is the problem.

When the WiFi stopped working a few weeks ago, the bluetooth also stopped working. So both the WiFi and bluetooth did not work. Then, I ordered a replacement WiFi cable because I thought that the issue could come from there, and then I followed the steps here https://www.youtube.com/watch?v=tg5gNop2Cos&ab_channel=GRIBSOFT to replace the old WiFi cable. Surprisingly, the Bluetooth started working again, but the WiFi still showed "Wi-Fi: no hardware installed". I then ordered a second WiFi cable from a different seller, and again replaced the cable. But the outcome is still the same, the bluetooth works but the WiFi not.

After searching online, and like the post above MacBook is displaying the message "no hardware installed" when I click on Wi-Fi says, the issue could come from the Airport Card. Before ordering one, what I don't understand is: if the issue could be due to the Airport Card, how is it possible that the bluetooth works again after replacing the WiFi cable ? I even put back the old WiFi cable, and when I did, the bluetooth stopped working again. So the bluetooth works with the two new replacement WiFi cables I ordered, but not with the original cable. And the WiFi doesn't work at all with any cable.

This seems really strange to me. Either the issue comes from the Airport card, and then the bluetooth should not be working when the WiFi cable is replaced, or the issue comes from the WiFi cable, but then the WiFi should be working again after replacing the cable.

By the way, I tried any other way I found on the Internet, including resetting NVRAM and SMC, removing NetworkInterfaces.plist, reinstalling OS X, Apple Hardware Test and other possible fixes I found online. Nothing worked. So if the issue really comes from the Airport cable, how do you explain that ? If it doesn't come from there, and the above fixes didn't work, what else could it possibly be ?

I haven been searching for several hours, but did not find any explanation on this, so I thought I might as well ask. Thank you so much for your help

Answer 1

how is it possible that the bluetooth starts working again after replacing the WiFi cable ? I even put back the old WiFi cable, and when I did, the bluetooth stopped working again.

The cable is probably shorted (damaged) causing the RF signal to fail or the adapter to stop working as there is an electrical short.

Either the issue comes from the Airport card, and then the bluetooth should not be working when the WiFi cable is replaced, or the issue comes from the WiFi cable, but then the WiFi should be working again after replacing the cable.

It’s possible you have more than one issue at play. Cables, especially antenna cables don’t get damaged unless they are interfered with for some reason like a repair of some sort. They typically never move and can last (relatively speaking) forever. The Airport card has (at minimum) two radios on it: a WiFi radio and a Bluetooth radio. One of these could have failed but the other works fine.

In the linked posts you referenced, it made the mention that the “hardware was not detected.” There are two “sides” to the AirPort card - the part that talks to the logic board and the other that transmits and receives data; the transievers. If the part that connects to the logic board (PCIe) fails, the system can’t use it and thus, WiFi is down. If the radio dies, the system might see the device, but the radio just send/receives nothing.

By the way, I tried any other way I found on the Internet, including resetting NVRAM and SMC, removing NetworkInterfaces.plist, reinstalling OS X, Apple Hardware Test and other possible fixes I found online. Nothing worked.

I’m not surprised. Most of this is diagnosis by correlation and most people who prescribe this have no idea what any of it does. They just saw it said somewhere and think it solves things, but in reality it’s the inherent reboot that fixes things.

• SMC is your power control module. Things like fan speed, battery/power isses are fixed with this
• NVRAM hold pre-boot environment variables like what volume to boot from and the Bluetooth info to connect your wireless keyboard and mouse before macOS loads. It’s a shallow config file; to see what’s in there issue the connand nvram -pl to dump the NVRAM values
• Apple diagnostics is helpful (less so now than with older vintage Macs) but will only tell you an error occurs eith a device actually generating an error. If you WiFi radio dies but not the controller chip, there’s no error that’s generated.