Okay, I have really misunderstood Betaflight and driver fixer thing. You have to run the Impulse fixer EVERYTIME you connect an FC?
Anyway, after uninstalling Betaflight, reinstalling and running Impulse fixer, it found my old board. Tried the one that's in the Gremlin, can't find it. Run the fixer again...….finds it.
I loaded firmware to the "old board", no problem. It's not connected to anything so I have no idea if it's okay or not.
Did the same on the board in the Gremlin and it won't save the UART. Get this error on the save and reboot:
2019-07-27 @ 19:27:39 -- Unrecoverable failure of serial connection, disconnecting...
2019-07-27 @ 19:27:39 -- Failed to close serial port
Tried different firmware versions, no joy.
Board is fried? Move it all back to the old board, maybe?