Thanks for the replies but "It's dead, Jim".

Tried the flash. Surprisingly the flash took with no errors. But it still would not boot. Same symptoms.

Tried the on off charger trick and even fully charged a battery using my phone then swapped it into the 770 with no joy.

Guess I get to experience the fabled Nokia Repair service. It is all packaged up and will go out today. They claim 7-10 day turnaround so I might have it back by Christmas but I doubt it.

Oh well, I was looking for an excuse to the latest upgrade but I wish I could have backed up my repositories first.

David