923.Xx-Hot Fuser Service Check - Lexmark X642e Service Manual

FRU
5 Fuser top cover assembly
(thermistor, thermistor
cable)
Fuser to system board DC
cable
6 Fuser assembly
923.xx—Hot fuser service check
Error Code 923.xx, 924.xx, and 925.xx may display for a hot fuser failure.
CAUTION
The fuser may be hot, use caution before removing or servicing.
CAUTION
There is a danger from hazardous voltage in the area of the product where you are working.
Unplug the product before you begin, or use caution if the product must receive power in order
to perform the task.
Service tip: Set the Fuser Temperature to NORMAL before starting this service check. In Diagnostics mode, In
Diagnostics mode, select EP SETUP, and Fuser Temp.
FRU
1 Fuser assembly
2 Fuser top cover assembly
(thermistor)
3 System board
Fuser top cover assembly
Action
Check to make sure that the thermistor is installed correctly to J5 on
the fuser control card. If installed correctly check the cable for any
signs of damage. If any problems are found, replace the fuser top
cover assembly."Fuser narrow media sensor removal" on
page 4-88.
If no problem is found, check the fuser to system board DC cable for
correct installation at J1 on the fuser control card. If no problem is
found, check the fuser to system board cable for correct installation at
J10 on the system board. If no problem is found, go to step 6.
If no problem is found up to this point, then replace the following in
the order shown:
• Fuser assembly. See "Fuser assembly removal" on page
• System board assembly. See
removal —models X644e/X646e" on page
• LVPS. See "Low voltage power supply removal" on
page 4-109.
Action
Check for any signs of overheating in the fuser assembly. Check the
hot roll, hot roll bearings, and the area around the thermistor for any
signs of excessive heat. If a problem is found, replace the thermistor.
If no problem is found, go to step 2.
Turn the printer off and disconnect the fuser to system board cable
from J10 on the system board. Check the resistance between pins
J10-3 and J10-4. The resistance should be greater than 100K ohms.
If correct, go to step 3; if incorrect, disconnect the thermistor cable
from J5 on the fuser board and measure the resistance between the
two pins on the thermistor cable. If incorrect, replace the fuser top
cover assembly (see "Fuser narrow media sensor removal" on
page 4-88); if correct, replace the fuser to system board cable.
Check the voltage on J10-3 ground on the system board. The voltage
should measure approximately +3.3 V dc. If the voltage is correct,
replace the fuser top cover assembly. See
sensor removal" on page
board. See "System board and inner shield removal —models
X644e/X646e" on page 4-131.
"System board and inner shield
4-131.
"Fuser narrow media
4-88. If incorrect, replace the system
Diagnostic information
7002-xxx
4-79.
2-135