Hello georgej54 - Welcome to the Sony Forums 
First of all, I would suggest trying to reset the camera to its factory settings so see if this resolves the problem. This feature can be found in the Setup menu.
If that doesn't help, that would indicate that there is some kind of internal fault within the camera and in the first instance, I would recommend contacting Sony Customer Services to see if a repair would be a feasible option. The contact details are in this forum thread:
http://www.sony.co.uk/discussions/message/651957#651957
Thanks,
Simon