DVD player not able to start the disk spinning?

I have a Sony DVP-NC600 CD/DVD player. Now when I put in a CD or DVD to play, after some time of the player trying to play, it showes the notice that there is no disk. I took the case off and if I load a disk it is not able to start the disk spinning and thus not playing but if I start the disk spinning by hand the machine will continue to spin the disk and play untill it is turned off. Once turned off and the disk has stopped spinning it will not play again unless I start the the disk spinning by hand.

What part needs to be replaced and where can I get it?

Thanks
Brian