Serial number : 1 4020 1305 02282 When we turn the unit on . The message appears : CORE 020-4020-24R01 C656 Initialializing 1. When we press Reset button the wheel turns on top and on the bottom . 2. Speed button works from low * to high *** 3. When press Add button on the right Add button in the left light up. 4. Density operation works from * to Off 5. When SD button pressed noting is happening . 6. Gray dial on top moves freely 7. When Strap button press you can choose limits between 1 to 100 8 . When we placed one index cart on top in the hopper , the roller starts rolling on top and on the bottom ,but the paper goes in very slowly and jams . So this machine possibly needs some cleaning . No other testing was done . Might or might not need some repairs .