Fuser Unit Error (Error C41A,C41B,C449,C446,C41C,C41D,C468,C466); Error Occurs Immediately After The Power Is Turned On; Error Occurs Approx. 1 Minute After The Power Is Turned On - Oki MC760 Maintenance Manual

Oki Data CONFIDENTIAL

7.5.4. (11) Fuser unit error (error C41A,C41B,C449,C446,C41C,C41D,C468,C466)

(11-1) Error occurs immediately after the power is turned on.

Check item
(11-1-1) Thermistor is defective Note)
Upper thermistor, Check the respective thermistors if they are
lower thermistor, shorted or opened internally.
frame thermistor Check the resistance value at the connector pins
in the bottom of the fuser unit.
(Refer to section 8.1 Resistance check (fuser
unit).)
Installed condition of Check if the fuser nit is pressed in until the
fuser unit. connector in the bottom of the fuser unit is surely
connected.
Note! Service calls C41B error and C41D error can occur when the printer
temperature is below 0 . Turn on the power again after the printer temperature
has increased.

(11-2) Error occurs approx. 1 minute after the power is turned on.

Check item
(11-2-1) Temperature increase of fuser unit
Thermostat, halogen Heater of the fuser unit is controlled of its
lamp temperature. Check if the fuser unit gets hot or
not by touching it with hands.
If the fuser unit temperature does not increase
and remains cold, check that the resistance
between pin-1 and pin-6 of connector A, and that
in between pin-1 and pin-6 of connector B of the
two connectors is in the range of several ohms to
several ten ohms respectively. (Refer to section
8.1 Resistance value (fuser unit).)
45376001TH Rev.1
Action to be taken
Check work
at NG
Replace the
fuser unit.
If any attempt of
using new fuser
unit as a trial
is going to be
made, be sure to
use the System
Maintenance
Menu FUSE
KEEP MODE.
Re-set the fuser
unit.
Action to be taken
Check work
at NG
Replace the
fuser unit.
If any attempt of
using new fuser
unit as a trial
is going to be
made, be sure to
use the System
Maintenance
Menu FUSE
KEEP MODE.
Check item
(11-2-2) Temperature increase of fuser unit
Installation position Check if the upper thermistor is installed in the
of the upper far position from the specified position or not
thermistor causing detection of the lower temperature than
the actual temperature of fuser unit.
Remove the heater cover, and check warpage of
sensor by visual inspection.
Installation position The lower thermister must be installed while
of the lower contacting with the fuser unit. Check if the lower
thermistor thermister is installed in the far position from the
specified position or not causing detection of the
lower temperature than the actual temperature of
fuser unit.
(11-2-3) AC power input to the halogen lamp
AC power voltage Check if the AC voltage for heater is normally
from the low voltage supplied or not.
power supply Power supply CN2 connector
and pin-2, and between pin-3 and pin-4.
Heater ON signal Check that the heater ON signal goes active at
that is output from the warming up timing, or not.
PU to the low voltage "L" active while ON.
power supply Power connector
pin-14 and pin-16.
7. Troubleshooting and repair procedure
Action to be taken
Check work
at NG
Replace the
fuser unit.
If any attempt of
using new fuser
unit as a trial
is going to be
made, be sure to
use the System
Maintenance
Menu FUSE
KEEP MODE.
Replace the
fuser unit.
If any attempt of
using new fuser
unit as a trial
is going to be
made, be sure to
use the System
Maintenance
Menu FUSE
KEEP MODE.
Replace the low
voltage power
, between pin-1 supply.
Replace the PU
board.
of the PU board, between
185 /