MX3500N  SELF DIAG AND TROUBLE CODE  8 – 17
 
F2-50 K phase sensor sensing trouble
 
F2-51 CL phase sensor sensing trouble
 
F2-58 Process humidity sensor trouble
 
F2-64 Toner supply abnormality (BLACK)
 
F2-65 Toner supply abnormality (CYAN)
 
F2-66 Toner supply abnormality (MAGENTA)
Trouble content Detection is made by interruption of light in the sensor 
section of the projection rib on the drum drive gear to 
control the BK drum phase. The detection signal 
cannot be acquired and phase control cannot be 
made.
Section PCU
Case 1 Cause Sensor connector connection trouble
Check 
and 
remedy
Check the sensor connector connection.
Case 2 Cause Dirt on the sensor light emitting section, or installation 
trouble
Check 
and 
remedy
Check for dirt on the sensor or check the installation 
state. 
Case 3 Cause Drum drive gear upper rib breakage, sensor trouble
Check 
and 
remedy
If there is no trouble in the rib, replace the sensor. 
(Use SIM30-1 "DHPD_K" to check interruption or 
transmission of light.)
Trouble content Detection is made by interruption of light in the sensor 
section of the projection rib on the drum drive gear to 
control the phases of all the color drums. The 
detection signal cannot be acquired and phase control 
cannot be made.
Section PCU
Case 1 Cause Sensor connector connection trouble
Check 
and 
remedy
Check the sensor connector connection.
Case 2 Cause Dirt on the sensor light emitting section, or installation 
trouble
Check 
and 
remedy
Check for dirt on the sensor or check the installation 
state. 
Case 3 Cause Drum drive gear upper rib breakage, sensor trouble
Check 
and 
remedy
If there is no trouble in the rib, replace the sensor. 
(Use SIM30-1 "DHPD_CL" to check interruption or 
transmission of light.)
Trouble content Process humidity sensor open
Section PCU
Case 1 Cause Process humidity sensor harness connection trouble
Check 
and 
remedy
Check the harness and connector connection of the 
process humidity sensor. 
Case 2 Cause Process humidity sensor trouble
Check 
and 
remedy
Check the process humidity sensor. 
Case 3 Cause PCU PWB trouble
Check 
and 
remedy
Check the PCU PWB. 
Trouble content Toner end with the remaining quantity of 50% or more.
The toner supply time exceeds 3 times as much as 
the specified time. 
Section PCU
Case 1 Cause Toner motor section connector harness trouble
Check 
and 
remedy
Check the connector connection of the toner motor 
section.
Check the connector harness (TM) connection to the 
main PWB.
Case 2 Cause Toner motor and toner density sensor trouble
Check 
and 
remedy
Check the toner density sensor output. (SIM25-1)
Check that the toner transport pipe is not clogged 
between the toner cartridge and the developing unit. 
Replace the toner cartridge (CRUM) if necessary. 
If replacement of the toner cartridge (CRUM) does not 
clear the trouble, check the developing unit.
Trouble content Toner end with the remaining quantity of 50% or more.
The toner supply time exceeds 3 times as much as 
the specified time. 
Section PCU
Case 1 Cause Toner motor section connector harness trouble
Check 
and 
remedy
Check the connector connection of the toner motor 
section.
Check the connector harness (TM) connection to the 
main PWB.
Case 2 Cause Toner motor and toner density sensor trouble
Check 
and 
remedy
Check the toner density sensor output. (SIM25-1)
Check that the toner transport pipe is not clogged 
between the toner cartridge and the developing unit. 
Replace the toner cartridge (CRUM) if necessary. 
If replacement of the toner cartridge (CRUM) does not 
clear the trouble, check the developing unit.
Trouble content Toner end with the remaining quantity of 50% or more.
The toner supply time exceeds 3 times as much as 
the specified time. 
Section PCU
Case 1 Cause Toner motor section connector harness trouble
Check 
and 
remedy
Check the connector connection of the toner motor 
section.
Check the connector harness (TM) connection to the 
main PWB.
Case 2 Cause Toner motor and toner density sensor trouble
Check 
and 
remedy
Check the toner density sensor output. (SIM25-1)
Check that the toner transport pipe is not clogged 
between the toner cartridge and the developing unit. 
Replace the toner cartridge (CRUM) if necessary. 
If replacement of the toner cartridge (CRUM) does not 
clear the trouble, check the developing unit.