Thanks, all. Took 4x reflashes with lots of reboots between, but all mining now. I'm keeping it on ECO mode just to see how long they'll mine without any big issues. So far 18 hours without any issues.
Great, all is clear now what has happened. As n0nce said, please be careful not do damage anything else so you don't lose any warranty.
So you have both standard miners mining OK via USB cable, one perfect one and one with some HW errors. But HW errors themselves are not such a worry.
But you determined your Orange Pi from Full Unit is not mining, with whatever miner board connected to its back, you tried two miners. That's not good. Board is online, bitcoind syncing, but not mining with the board connected by GPIO. Right?
I know there are two SD card images to download, for old batch boards and new ones. Which SD card image did you try? What batch is your miner, a new one?
I used the new SD card image as mine was batch 4 (build sometime in July 2022).