Disklavier

The other day, I noticed that the DKC55RCD controller for my DC3A wasn't reading my floppy disks. It would sort of grunt twice, then give up. 

A few days later, I got a can of compressed air, sprayed it into the slot, loaded a floppy, and it worked fine. I thought, "Okay, it was just a little dusty, and now it's fixed." 

Wrong!

Now it's doing the same thing again, and a lot of spraying hasn't helped. 

Does anyone have any suggestions for getting it to work again? Is it possible to open the unit up and replace the drive?

Thanks.

--James