I have a Sony 19 micron head hi fi stereo VCR. It worked great for a long time and on the tape I just watched. When I put in the next tape the picture fluttered at times and there was no sound. I tried other tapes and most were the same but for Heavy Metal. The picture fluttered but less and part of the music sound track was at a much lesser volume than the voices. Again my other tapes that I tried had zero sound and the picture fluttered more. Is there some easy fix for this?