The most likely fault is the CD in switch. They are not easy to find a replacement for but can be cleaned with alcohol and re-greased.
Thanks.
I think I've determined it's the laser pickup at fault. When you insert a disk, the laser head moves up and down a few times looking to find focus but fails. From what I have found that's the first thing it does, only when it's found focus will it start spinning the disk.
So the question has now become where can I get a laser head assembly for this deck?