hifi engine

KR-A5030 left channel for speakers out

I bought this goodwill and whoever had tested it had put note on the back saying"Works it the left channel for the speakers are out easy fix". I recently retired due to diagnoses of MS, so I'm trying to find some hobbies. I know a little bout electronics and just asking for help on this. I need manual and service manual if I could. Thanks very much in advance.