Turntable channel imbalance

I had this happen to me a while back and found that one of the conductors from the tonearm to the output terminal was failing, making that channel much quieter than the other. I installed a new wire and all was fine. 

Try the anti-skate adjustment and see if that helps!

Reduce antiskating and see. If you have a tubed phono check tubes.

Thank you. Is anti-skate adjustment available on a p-mount deck?  I don’t see instructions for it in the manual. Thanks!