So I took a look at my 2nd thrift store "score", and it only has the single disc cart. It will bring the disc into playing position but doesn't recognize that there's a disc there, and spits it right back into the cart. Never tries to spin up. Anyone know what microswitch (?) detects a disc presence so I can clean it? Also, take a look at this photo. Is the laser supposed to look like this? It appears to me that I'm gonna need a new laser even if I can fix the disc detection problem. http://imgur.com/a/uKf91 thanks!