dual cs 503-2 left stereo sound stronger
I got given a deck, a dual cs 503-2, by a friend and went out and bought some second hand (VG condition) vinyl from Flashback. Nick Cave's No more shall we part.
All was good and I had a listen last night, but this morning while listening to a new side, the sound went quite high pitched and much louder on the left. Like it had run into a scratch on the vinyl, there are a few.
Now I only get sound from the left hand speaker, there is sound on the right, but barely amplified. Checking using my DAC the amp is fine and there is sound from both speakers.
So how do I fix my deck so that it gives me sound from both channels. It is an old deck and has been unused for years I think, but lightly used before that, maybe 100-200 hours tops. There are 0-2.0 dials at the end of the arm, what should those be set on?