See this excellent user tip from another forum member turingtest2 outlining the other methods and software available to help you copy content from your iPod back to your PC and into iTunes.
It's hard to say for sure what is going on for sure at this point. I would try some of the other methods and software outlined above.
Thanks for your interest, PlanB,
I've had help before from turingtest but I omitted to say that absolutely everything on my iPod is from my own CD collection, so there was nothing there from the iTunes shop I could recover. I'm working my way through the list that tt provided of software but so far no joy.
It's beginning to look more and more as if my iPod is at fault as - in addition to the loss of sound - now it shows that a tune is playing but the marker that shows playing progress through the track isn't moving (doesn't even appear at all). Not that I could hear it anyway. I rather think I have what your hear described as 'a lemon' or a 'Friday afternoon job' - or it's equivalent in China.
Appreciate your help.
Incidentally when the iPod is mended or replaced I will post the fact. I am posting today for help in creating backup from an iPod on to a computer.
PS. Are you really on Easter Island?