cd player wont recognize cds?

I have a JVC model CA-UXLP5 that has been a wonderful addition to my classroom, until last Friday when it quit recognizing CDs that it's played fine before. I've tried oves it's played before as well as brand new ones. It says 'reading'we (for a longer time than usual) then says 'no disc'. I would REALLY like to have it working again.