Ah yes, sorry I missed this…
When you said earlier that you tried to follow the manual firmware update (https://wiki.newae.com/Manual_SAM3U_Firmware_Update), did you short your Pro’s “erase” jumper? You’ll have to open the case but it should work. It should bring it back to bootloader mode. Follow exactly all the manual update instructions (but use the right FW image this time 
)
Jean-Pierre