Lexmark Optra S Service Manual - Page 77

4059-XXX Hot Fuser Service Check Error codes 923 and 924 may display for a hot fuser failure. CAUTION: The fuser may be hot, use caution before removing or servicing. FRU 1 Fuser Cover Assembly (Assembly includes Thermistor and Thermal Fuses.) 2 Engine Board 3 Fuser Hot Roll Backup Roll Bearings Action Check for damage to the thermistor assembly. Check the resistance of the themistor: HOT - J2-1 to J2-2 = 2.5K ohms COLD =150K ohms to 260K ohms Check the continuity from each pin of J2 to ground. If there is continuity, replace the fuser cover assembly Error code 924 indicates the engine board detects an open circuit in the thermistor circuit for the fuser assembly. The voltage on J2-6 on the engine board measures approximately +5 V dc. If incorrect, replace the engine board. If correct, check the continuity of the DC fuser cable connected between J2 on the engine board and J1 on the fuser control board. In there is no continuity, replace the cable. If there is continuity, check the voltage on J2-2 on the fuser control board. It measures approximately +5 V dc. If incorrect, replace the fuser control board. Examine the fuser assembly for signs of overheating or damage. Check the hot roll and backup roll for signs of excessive toner, label glue, labels or other contaminants. If any are found, repair as necessary or replace the fuser assembly. Diagnostic Information 2-50