Lexmark Optra C710 Service Manual page 118

5016-001
920 and 921 Error codes
FRU
1 Thermistor
2 Engine Board
HCU Cable
.
2-52
Service Manual
.
Action
Be sure the thermistor is clean and positioned
properly. Check the following resistances of the
thermistor:
• Hot: (CN18-1 and CN18-2) (engine board)
should be approximately 2.0 - 2.5 k ohms.
• Cold: Should be approximately 150k to 250k
ohms.
If incorrect, replace the thermistor.
Check the HCU cable and fuser to engine board
cable, to be sure the contacts in the HCU cable
(the autoconnect) are not bent or damaged.
• If damaged, replace the HCU cable.
• If the no damage is detected, be sure the
cable is installed correctly at CN18 on the
engine board. If the cable is good, replace the
engine board.
Error codes 923 and 924 may display for a hot
fuser failure.