I bought a in-very-good-condition-with-extras DevTerm from another forum member, but elected to replace the A04 with my own CM4 (the seller had included a CM4 carrier board).
(First off, I see how Clockworkpi had a lot of lessons learned from DevTerm and applied them to the uConsole (which I also own)–the assembly process for the uConsole is much easier and the overall build sturdiness much more so with the metal screws and plates. The only thing I wish the uConsole had was the battery hatch).
Well anyway, i disassembled the DevTerm, replaced the A04 with the CM4 + carrier board, downloaded AK-Rex’s image, edited the config file and booted up.
The DevTerm booted up fine but the only problem was the keyboard and trackball were NOT working. I rebooted and connected a keyboard and mouse via USB via both sets of USB ports and no joy.
Long story short, if this happens to you, and you’ve tried re-seating full disassembly to see if the pogo pins for the keyboard may be the issue or some other thing**–try re-seating the CM4 on the carrier board**. That’s what fixed it for me ultimately. Weird that the DevTerm still booted up–just without any USB devices–but hey it worked.