Description: Polygon motor does not synchronize with the reference clock.
Code: 72
Description: Cannot detect Beam Detect signal.
Code: 73
Description: No toner cartridge loaded.
Code: 74
Description: Toner empty.
Code: 75
Description: In-casing temperature error.
Code: 76
Description: Heater harness disconnected or broken. Or heater thermistor harness disconnected or broken when the power is turned on, the top cover is opened and closed, or the machine exits from the sleep mode.