Thanks for your reply, I will take a read through those pages. In the interim, it initially froze during normal use, then restarted a couple of times with me trying the 30 second power switch method to restart. Then froze for good on the menu screen. Charged via wall socket for 2 days, although the orange light stays on for an hour or two before going off. No sign of the green light. Removed battery and reinstalled it, tried recharging and no change on the screen.
I just plugged it into the computer and it does not show up on the device list.... tried the power switch and the volume key and no beeping or sign of any device, althought the light does go orange when it is in the computer.
Many thanks for any help