Blue screen on playback on Sony DCR-HC40

Question

Hi - when I switch the Camera into Playback mode and hit play it simply displays a blue screen. I can hear the tape moving and tried several tapes but nothing works. Recording appears to be working and its not a problem with the LCD because I can see the picture in it when I am recording. 
Any tips on what I could do? Its a good cam corder in great shape. Would hate to have to dump it.