Toner sensor service check
Service tip: Check the print darkness menu setting before checking the toner sensor.
This service check is intended to be used when a 929.xx Service Error displays.
Developer drive assembly
Front harness cable
Incorrect operation of the developer drive assembly can cause the
printer to display a 929.xx error code (Toner Sensor). Check the
developer drive assembly for correct installation or, any sign of worn,
loose, or broken parts.
Check the toner sensor portion of the front harness cable to make
sure it is properly seated into the toner sensor. If correct at both the
sensor and system board (J15), check the continuity of the cable. If
incorrect, replace the cable.
The toner sensor cable is part of the front harness and part of
connector J15 on the system board. Check the voltage at J15-11. It
reads approximately +5 V dc. If incorrect, replace the system board.
If correct, check the voltage at J15-12. It reads approximately
+5 V dc with the system board removed from the printer. If incorrect,
replace the system board. If correct, replace the toner sensor
assembly. A bad ground connection between J15-13 on the system
board and pin 3 on the toner sensor results in a 929 service error.