From your limited desciption of your problem, I would guess that you are playing damaged tape. That would account for the lines and lack of sound. I have had that problem with a Sony Hi-8 camera for years. Most distressing when it was a wedding video.
I was told not to switch tape brands, and to clean the heads with an abrasive head cleaner. The best thing I did was to upgrade to mini dv. I've still got a lot of Hi-8 tapes I need to convert to dvd.
I own an old (17 years) Sony Video-8 camcorder (analog). and am beginning to copy the family tapes we have to DVD's. I am having trouble with the camcorder on playback and am now getting ''hash'' lines (noise lines?) across the playback screen both in the camera and on the TV screen - when this happens, there is no sound. It doesn't seem to be consistent. Doex anyone have any ideas about a correctioon of this? I tried cleaning the head, but no change. I do believe the tapes are OK. Any help would be appreciated. Thanks,