4 • Troubleshooting/Diagnostics
4.2 Troubleshooting Tables
Table 4-7 Print Carriage Faults
PS1 fails to sense envelope or tape lead edge.
fails to move from
Carriage home sensor.
home to print po-
NOTE: It is nor-
Carriage drive stepper motor.
mal for the print
head to move
back to the home
position if an
Carriage drive belt.
envelope or tape
is not sensed by
PS1 for 15 sec-
Carriage drive rails.
And grinding noise.
Check for debris in transport path. Check PS1
using service diagnostics.
Sensor is blocked when carriage is in the
home position. Use service diagnostics to
check sensor status. Also check harnesses
from Purge Unit to J116 and J120 on Main
Logic (Controller) Board. Any error messages?
Check motor using service diagnostics. Also
check harness between motor and J118 on
Main Logic (Controller) Board.
Inspect belt and pulleys. Check that belt is
centered on pulleys and fully engages loop on
Check that carriage assembly is not binding
on rails. Assembly should move freely.
If the purge motor fails to turn clockwise with
the carriage assembly in the home position,
the printhead lock and cap will remain up,
preventing movement of the carriage. Test the
purge motor using the service diagnostic rou-
tine. Also check the harnesses from the purge
motor to connectors J116 and J120 on the
Main Logic Board.
Indicates carriage motor failure or wiring
problem. System locks when error message
is cleared. See Carriage drive stepper motor
Possible problem with cap motor or sensor
located in purge unit. System may lock when
error is cleared. Use service diagnostics to
check. Also check wiring to Main Logic Board,
J116. In addition, check purge motor and wir-
ing to Main Logic Board, J120.
DM300c/DM400c/DM475 Service Manual (SV61801 Rev. D)