What is the transport model?? Most Sony transport are built like a rock.
My ex- Denon DCD1520 used a Sony KSS151A, a Peterbilt transport.
Usually these good transports from the past last a century.
If you live in a cold or humid area, the lens also get humid or dusty.
So you need clean the lens with a wet cotton swab + neutral soap bar + mineral water(without chlorine).
Please Note: it is little water and little soap; if you wet the transport PCB inside the lens cover it may damaged permanently! So proceed carefully.