Need 1984 SONY CDP 701 ES repaired

I have a Sony CD player from 1984, model CDP 701ES that needs repair. The disc tray extends out and stops - with a disc it retracts into the machine - and that is all. There is a red LED that indicates the player does not recognize the disc is there. I doubt the laser is damaged, the player never had that much use. Why bother? Because this player (otherwise) is in pristine condition without a mark on it. To a collector it must have some value. Any thoughts?