Try pushing the lens assembly to the inside of the drive mechanism. None of the cleaning steps seemed to work for me.
I noticed the trolley holding the laser lens assembly was always in the outside position when I opened the drive. I physically moved the trolley to the inside near the hub where the DVD attaches to the drive mechanism. Careful not to touch the lens though.
I think the lens assembly had gotten stuck on the outside edge of the drive mechanism, and couldn’t move anymore.
Then I put a DVD in, and it worked!