why do cd players "sometimes" not read a disc?

My Lexicon RT-20 is sometimes refusing to read a disc that has just been playing?

ptss09-20-2013 3:55am

newbee Details Discussions Posts This discussion Message User 4,093 posts 09-20-2013 at 03:03pm Copy Comment URL Report Comment Edit Delete Often it is because the laser has become dusty/dirty and a simple cleaning will take care of the problem.