[Jukebox-list] Rock-Ola CD8C error message question.

Hello all.  I have a Rockola Bubbler CD8C and when it is turned on, it give a ERROR message in the display. it says DIAGNOSTICS MODE    CD Comm. Failure. Where do I start?   Does anyone think it is possible that the board inside the CD PRO Player went bad?    Hoping for some experienced folks to point me in the right direction. Thanks,Ron B