I have a 2005 Ford Focus with a Sony 6 CD player. Just recently when I start the car the display doesn't come on although it plays the radio and CD okay. It's a pain because you can't see what CD is on, or what radio station is on, or the menu options. But, on very rare occasions it does come on. Has anyone had a similar problem?

Could be a loose conection , i would take it apart unplug and then plug the screen section back in or it could be a dry solder joint causing it.

Agreed, and since the car has no warranty, you dont really have that much to lose. Call your local dealer, ask them if they have seen this before. If you are not confident doing it yourself, they may charge you less than an hour to do what could be to them, a 10 minutes job.