It LIVES!
So just to close this off - after taking it apart a couple of times and testing where everything worked, everytime I reassembled and tested it didnt work.
In the end I gave in and dropped it to Wolf Armouries.
The tech initially had the same issue as I did with parts working when disassembled and then not working when assembled. He finally traced the fault to a tiny bit of corrosion on the motor that the initial drop must have dislodged.
I'm happy to have the gun back - working and serviced with new lipo connections and happy with the service I recived from Wolf.