Hi, sorry for the delay but have been on holiday. I dont know what you mean by firmware, is this the same as update ? if so then doesn't this occur with the shipping reset?
Thank you for your comments and I managed to find the updating sections but only found that the latest had downloaded automatically and the unit was completely up to date.I note that the repair is probably uneconomic and so I will leave it and thank you for your help, at least I know the situation rather than guessing.
ps. am going on holiday again tomorrow so will look for a replacement recorder when I get back.