My model is JVC GR-DX28EK.
I have just had difficulty with a similar issue. Lens Cap flashes for the 5sec initial period and then no image - almost as though the light is not travelling through the aperture in order to pick up an image.
I have recorded and the camcorder works superbly, sound is picked up but the image recorded is the blank screen.
I have just spoken to JVC technical support (0208 208 7654) and the gentleman has informed me that this issue is a manufacturer's fault across the range of JVC camcorders and they are repairing camcorders with this fault free-of-charge, whether within or without the products guarantee.. Which I feel is very kind of them and I'm utterly relieved as my camcorder works fabulously in everyway and I though I was going to lose it.
I hope this is a help to you and others seeking answers..
R xx
Rebecca, May 2009