CD Player Yamaha CDX-493 opened up for maintenance + bad CDs

My "Yamaha Natural Sound CDX-493" CD player stopped recognizing and playing CDs, so it was time to open it up for the first time since I bought it in 2000. I only had to perform some simple maintenance instead of repairing it: mainly dusting off the lens. Afterward I tried playing some of the worst-condition CDs from my collection. I didn’t record the actual work I did, but I hope the video will still be helpful to anyone who wants to take a look inside.