Something could be stuck in the drive causing it to continually open and close. Or, the button is shorted out or stuck pushed in. Causing the drive to think you are constantly pushing the button trying to open the drive. Hit/push the button on the front of the drive a few times to see if it un-sticks it. Also use a pin and push it into the emergency eject hole. You know, that little pin hole on the front of the drive. See if doing that causes the drive to stop going crazy.