My thanks too to jnjroach. Unbelievably this solution worked. I had spent several days searching for a solution to my dead Pro3, wondering how to recover data etc. I taped the power button down and left the power supply plugged in overnight and the next mornig the Surface started up as if nothing had happened. I am gobsmacked by the solution and having been in the IT industry for the past 30 years I am not easily impressed. Again, a million thanks to jnjroach!