Lexmark CS720 Service Manual page 170

Error code Description
121.33 Fuser did not reach the required temperature while
the page is in the fuser.
121.34 Fuser did not reach the required temperature
during steady state control.
121.35 Fuser too warm to power up and execute EWC/line
voltage detection after a wrong fuser was installed.
121.36 Open fuser relay was detected in very cold or
unknown ambient temperature.
121.37 Fuser heated too fast during final EWC/lline voltage
detection.
121.41 Fuser mechanism did not detect the expected cam
sensor signal.
121.42 Fuser gate time increasing out of control.
121.48 Fuser type does not match the fuser driver.
121.50 Fuser went over the required temperature during
global over temperature check.
121.51 Fuser secondary heater is too hot.
121.70 Heater resistance is too high.
121.71 Open fuser main heater thermistor was detected.
121.72 Open fuser secondary heater thermistor was
detected.
121.73 Open fuser middle heater thermistor was detected.
121.74 Open fuser edge thermistor was detected.
121.76 Open contact belt thermistor was detected.
121.81 Open fuser backup roll thermistor was detected.
121.82 Open fuser second backup roll thermistor was
detected.
121.83 Open fuser narrow media backup roll thermistor
was detected.
121.84 Non‑contact sensor (BUR) is missing.
Action
See "Fuser service check" on page
Diagnostic information
170
5028
184.