Lexmark 522n - C Color Laser Printer Service Manual page 86

4520-xxx
Hot Fuser Service Check
Error Code 923: Indicates the fuser is too hot during printing or when
the printer is idle.
Error code 924: Indicates an open circuit has been detected in the
fuser thermistor circuit.
Note: Check the fuser sub error codes to help diagnose between a
923 and 924 error.
CAUTION: The fuser may be hot, use caution before removing or
servicing.
FRU
1 Fuser Cover Assembly
(Assembly includes
Thermistor and Thermal
Fuses.)
2 Fuser Control Board
3 Fuser to Engine Board DC
Cable
2-58
Service Manual
Action
Check for damage to the thermistor
assembly. If damage is found,
replace the fuser top cover
assembly. If no damage is found,
check the resistance of the
thermistor between pins J6-1 and
J6-2 on the cable.
• HOT = 2.5K ohms
• COLD =150K ohms to 260K ohms
If the resistance is incorrect, replace
the fuser top cover assembly. If the
resistance is correct, check each pin
of J6 to ground. If there is continuity,
replace the fuser cover assembly
Check for continuity between J6-1
and J1-2 and between J6-2 and
J1-3. If incorrect, replace the fuser
control board. If correct, go to step 3.
Check the continuity of the cable. If
incorrect, replace the cable. If
correct, go to step 4.