Hello,
I am sorry for just now responding to your request. I would go ahead and clean the optical reader as this is the most likely problem. If you listen really close when the disc is loaded and it appears to spin up then the problem should not be your spindle motor. Clean the optical reader first and attempt to replay the dvd. Also check to make sure the dvd is not scratched or damaged in any way that would prevent the laser from picking it up and reading the disc. You can find details of how to clean the optical reader in my tips. Again, I am very sorry for my late response as I have been out of town. Let me know if you need further assistance.