DVJ-X1 disc load issues

I've recently got hold of a couple of old DVJ-X1's, one is working fine but one has problems loading discs.

On power on it won't accept cds or dvds, there's an audible light grinding sound before it ejects the disc back out. I've uploaded a video here: https://www.youtube.com/watch?v=KLdEemsV1G8 

If I persevere it will eventually load a disc, although it can't read it if it's a cd but dvd is fine. From then on it works fine with both cds and dvds.

When I power off and back on I have to repeat the process to get it working again. If a disc is already loaded when I power on, it makes the same grinding sound and ejects the disc.

Does this sound like a familiar issue? The decks look well used so this could be just wear and tear so I'm wondering if it's possible to economically repair.

Incidentally I tried a firmware upgrade but it seems if it can't load the disc first time when it eventually reads it it thinks it's a music disc.

Many thanks