Try this on your bricked unit.
1. With your truck on and wireless CarPlay running search 192.168.50.2 it should show you the firmware update to 8-4-20 on your phone. Keep this page open.
2. Connect the bricked unit to the wall power brick.
3. Connect a iPhone/iPad lightning cord to the bricked unit.
4. Connect your phone to the lightning cord.
5. Now press the update firmware tab on safari on your iPhone screen and let it go through the process.
6. This worked for me on my Carlinkit usb-c once when I couldn’t get it to do anything.
Well, again, I'll be a blue-nosed gopher. This actually worked! I have a resurrected CPlay2Air unit now!
I did exactly as Denali outlined. After plugging into the lightning cable, I clicked "Update", it slowly worked its way from 0% to 100%, then gave me a spinning ring with the message "Upgrading, please be patient, this could take a while". It then reported, "Upgrade Complete". So I unplugged everything, took it back out to the truck and BAM, it came back to life! Head-unit saw it, and I was able to join it with my phone. All good!
Now here is the weird thing: After joining the adapter's WiFi manually in the truck, I navigated to 192.168.50.2 and it reported the firmware as 7.17 (which is what was on the adapter when I bricked it)! So I disconnected, and reconnected via Bluetooth (which then handed off to WiFi) and re-navigated to 192.168.50.2 and it is now offering to "Discover a new version..." to 2020.08.04.xxxx. I was too scaredy-cat to try another OTA update, so I shut down and have brought everything in the house to do a manual USB update to 2020.08.04 and see if that works.
So, to sum up, I am not totally sure exactly HOW this works, but it certainly does. I had a totally unresponsive, completely dead / bricked, CPlay2Air adapter, that would show absolutely ZERO lights, in the truck or when plugged into a power adapter, that now is working again. And while I'll be the first to admit that I was very skeptical about this technique, given my years of experience with networking and routing, I am extremely happy to report that it works! Or at least it did for my bricked unit. YMMV.
@2018 Denali, I don't know what kinda cereal you eat for breakfast, but it must be the "breakfast of champions", because once again, you my friend, "are da freakin' man"!
When inserting the Lightning cable. Does the phone say it is charging? I got a bricked unit which is not recognized by my car and the LEDs are not showing any sign of life. When I plugin the lightning cable, my iPhone won't charge. So is my unit really dead?