My video Carmera has no picture, but can still record sound, Why?

One evening I prepared my Video camera for the next night, I was going to a graduation, I put the tape in got it ready checked it, everything was fine, clear picture everything the next day, at the graduation, I went to use my Panasonic (Digital Image Stabilization EIS Palmcorder 700Xdigital zoom) I could turn it on, I could see the time, date, and bring up the menu both on VCR mode and Camera mode, But all i can get is a black screen. If I press record it will record sound but of course no picture. What could be wrong? What can I do (if anything)? Please if anyone can help contact me at Candie2026@yahoo.com Subject: Palmcorder help Thanks