Samsung camcorder: ow to make tapes stop sticking to head? ?

The camcorder appears to record correctly (it looks ok when I review while filming) but tapes either won't play or play with fuzz on the screen: the cassette reels turn, but too slowly, it seems. I have tried cleaning the rotating head, and the tape - but the tape clings to the head and stops it spinning, even when you just try to load the cassette