I've tried two different null modem cables, and both connect using the clone firmware updater. Neither will connect with the official software, it just says "stb memory error".
I have tried lots of different firmwares for my F5, even the F5s firmwares to see if it would make a difference. All firmwares download, and then reboot the box, and then hang at L093, then go to E001 after a short time.
I guess I just haven't found the right firmware yet?
Edit to add:
The red LED on the front barely glows, and there are no lights on the ethernet adaptor. I'm guessing its knackered?