Ej # 1 slot getting cd error not loading or playing

Try a new cartridge, they do warp over time. That would be "best case scenerio" worst case is the optic is shot/out of alignment, etc. There should be a reset button on the changer below the cartridge "(@)" small pen sized dimple that can be pushed w/a ball point pen to reset. How old is the unit? it's still in the current lineup. If it still doesn't work, call Alpine USA, give them the serial # if you don't have a receipt for it. They can tell you when it was manufactured to check for warranty status. Otherwise your looking at $100 - $150 repair. They would just swap out the transport. Best of luck!. Hope this helps!