I experienced exactly the same symptoms with my JVC grd20-ek. Checking on-line I found that this seems quite a common problem with this range of cameras and was most probably due to the failure of the CCD sensor.The local JVC dealer informed me that it would cost at least £200 to repair. The camera had been used very little (only 8 hours or so) but was about 18 months outside of the guarantee period so I contacted the customer services department at JVC. I expressed my disappointment at the failure of the component and enquired if there had been a product recall as the CCD sensor failure seemed to be very common. Unbelievably, I was instructed to submit full details of the fault and confirmation of purchase to JVC customer services. They then arranged for the camera to be collected, repaired and returned to me totally free of charge. So far, the camera is now working fine. This has gone a long way to restoring my faith in JVC and suggest you try a similar course of action.

Hello, I am also facing same issue. Did you receive any help or solution? Please advise. Thanks