Backend access all vending machines.
5 inches
Open the door and log in to the backend with your admin password.
Password: 123456, 123123
22 inch
Open the door. Then press the "ID" at the top left a few times.
Password: 888888
Other
Open the door. Use the keypad to enter the code "73194653" and then hold down the area above "Back" with your finger until the Admin menu opens.