How can I fix my Kenwood DP-2060 CD player?

The CD's will play for some time and then stop and the message "no disc" appears. When I then open and close it and press the track number to find the point at which it stopped (it is in track mode) it whirrs a bit and then goes to track 1, if I use the track forward button, it goes through the track numbers but then reverts to track 1 again. I have cleaned the CDs. Sometimes it will actually find the track, then I fast forward to the point and it will start to play normally, then it will stop again and either backtrack a little and play again or show "no disc". Any ideas on how to fix it?

Many thanks