How can I fix a Ford Focus EON 6000E EON (stock) in-dash CD player?

The car was repaired recently, and the power to the CD player must have been interrupted - I had to re-enter the keycode, but the CD Player display told me it had "no discs" which is not true - I had left 6 discs in the player.

I pressed Eject, to which the player replied "No Disc", so I tried pressing "Load" which made it recognise disc 1 and start to play, it then stopped and displayed "Error 3".

is there a way of getting this to work again myself, or do I have to get the dealer to have a look at it?

Thanks,