Lexmark 2390 003 - B/W Dot-matrix Printer Service Manual page 42

.
FRU
1 Carrier
2 Home Position
Sensor
Sub Logic Board
Short Flexible
Cable
2-18
Action
If there is no Home Position Error, check the
carrier belt and the ribbon cartridge for wear or
damage. Check the belt and pulley
engagement.
Manually move the carrier the full length of the
carriage to check for binds and to make sure
the ribbon advances when the carriage moves
in either direction.
If the carrier binds check the following:
• Correct printhead-to-platen gap.
• Clean and lubricated carrier shaft.
• Idler pulley not binding.
• Ribbon drive rack gear teeth not
damaged.
If the carrier still binds:
Remove the belt and move the carrier again. If
the bind is gone, replace the carrier motor. If
the bind still exists, replace the carrier.
If the carrier moves manually without binding
but the Home Position Error still occurs, verify
that the main logic board is receiving +26 V dc
on pin CP11-1. Check that the 5 V dc home
position sensor signal is getting to the main
logic board. Check CP3-7 on the main logic
board. Check CP6-1 on the sub logic board.
Replace the sensor, the sub logic board, or the
short flexible cable as necessary.