UPDATE
I have managed to connect a GPU by positioning the aircraft onto a ‘Stand’.
External power on - Bat 1 & 2 on - IR1,2 & 3 to NAV. APU switch ON - Start ON.
IRS’s align. But no running APU - unable to start. Plus fuel pumps L. Tank 2, CTR tank 2, and R. Tank 2 cannot switch pumps on.
Another aborted attempt and a huge waste of my time.
Don