Sony scd 777 es problems

My Sony scd 777 es is not functioning. I have tried it in another system with same problem. It seems to perform all functions correctly on the read out display, track playing, time, toc reading etc but no sound. I have had this unit for many years and love it( tho it is rarely used ). I am the second owner and the original owner sent it in for many upgrades including a super clock, resistors and caps. I can't afford a new unit of similar quality and am seeking suggestions on how to proceed. I live in lansing, Mi. And can't find any one to repair it locally. Thanks for the read.