Car C/D player only works occasionally how can I fix?

Peugeot 406 saloon 2lt X reg built in Clarion C/D player ( no Multi changer + un-coded radio) Works ok when ignition on, engine not running, start engine, player most times will not play.
Turn off/on and press other buttons will sometimes make it play. Original albums seem to work better than own recordings ( I understand home recordings can be inferior for play back and probably not work) I haven't tried to clean the laser yet though I have removed the unit, and taken off the top and bottom cover to have a look. Had no idea what I was looking at so replaced the covers and replaced the unit into the car. Seems to work a bit better but still not right. Is it possible to clean the laser with a cleaning disc, or do you think it's a bigger problem than just cleaning. I would appreciate any help you can give.
Best Regards Jim.