chopstick

Hey guys, I've owned my mz-nf810 for a couple years now and have really enjoyed it for the most part besides the hassle of uploading live recordings to my pc. so today I decided to put some music on on md and spent a whole bunch of time creating disc images to use with simple burner and when i finally got to the point of turning on my md to start transfering the darn thing won't read any discs! i tried many discs thinking it might be a bad disc, but no luck. the device just shows the spinning symbol and tries to read forever. i'm hoping that maybe i could clean it some how? maybe the lens? i used it the other day with no problems and haven't dropped it or anything so i'm a little stumped... any advice? thanks