Pioneer DVL-909 Fault

Can anyone help me please? I am in the UK and have just bought a second hand DVL-909 (european version). I've hooked it up to my Panasonic Plasma TV and the DVD playback works fine, however, the LD playback is fuzzy, almost like there is interference or its not tuning in properly. I still get sound ok but it does crackle a little as does the picture. I've noticed its worse on some discs than others but none have played properly so far. Its connected with a standard SCART lead. Does anyone have any ideas what I could do to check it out? Thank you! Ed.