Whilst this could be the end of the laser, it is not uncommon to find an issue with the inserts in the PCB that couple one side's tracks to the other. Over the years the solder dries out and intermittent connections result - does the player spin the disc up and then stop with a '?' in the display?
As to repair, I don't know anyone in the Midlands but arguably the UK's premier B&O guru lives in Surrey if you can get it down there?
Engineers: fixing problems you didn't know you had in ways you don't understand.