Toner Sensor Service Check - Lexmark T520 Service Manual

Infoprint 1120 and 1125

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 Service Error
displays.
FRU
1 Developer Drive Assembly
2 Front Harness Cable
3 Toner Sensor
2-102
Service Manual
Action
Incorrect operation of the developer
drive assembly can cause the printer
to display a 929 error code (Toner
Sensor). Check the developer drive
assembly for correct installation, 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 engine board (J10), 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
J10 on the engine board. Check the
voltage at J10-11. It reads
approximately +5 V dc. If incorrect,
replace the engine board. If correct,
check the voltage at J10-12. It reads
approximately +5 V dc with the
controller board removed from the
printer. If incorrect, replace the
engine board. If correct, replace the
toner sensor assembly. A bad
ground connection between J10-13
on the engine board and pin 3 on the
toner sensor results in a 929 service
error.