Playback tracking adjustment

Sounds like a mistracking problem, probably due to loosened up guides. Camcorder should be at least partially disassembled at its front where the tape is located in order to expose those guides (they look from above like normal big screws with a kind of protuberance at the center) thru which the tape traverses before and after the head drum. Then, with a lot of patience, they must be tweaked back and forth until playback resumes fine operation (there are more professional ways to do this with electronic instruments, of course, but if you only want to play back old tapes this should be OK for household purposes).
If this doesn't solve the problem, it might be a worn out / damaged video head drum, which should be replaced (a task best left to qualified professionals due to its complexity). Hope this helps. Bye and good luck !