I have the same problem with my system. There is a malfunction in the CD drive. Often a problem from age, and is common with systems that were made before the Arcade version. If it is just starting to happen sometime tapping on the door when you hit the open button might help. If that is not enough and you really can't access the drive, I would recommend trading it in and purchasing a newer console. The stores can tell you how to keep your save data depending on which system you have.