My Bose Radio CD Player has stopped playing CD's ?

This happened a couple of months ago. A cousin who is very good at fixing electrical equipment sent for a part and got it working temporarily but a couple of weeks later it was back to not playing. When you load a cd it looks as if it is going to work and then you get CD15 or something similar message on the screen. I have not got the model no here at the minute but can easily check up when I go home.