Sanyo VM-D66P camcorder playback function problem?

All other functions seem fine , I have cleaned the heads using the specified cleaning tape but the only way I can tell what I am playing back is to use the still/picture search/FF functions. As soon as I return to normal playback mode the picture is flickery to the extent that I cant tell what I'm looking at, similar to a video player whose tracking needs adjusting but there is no such adjustment on this machine. Any suggestions appreciated, also suggestions on service centres if they still exist.