Tractor Speed Too High; Tractor Speed Too Low - Printronix L5000 Series Maintenance Manual

14 – Tractor Speed Too High / 15 – Tractor Speed Too Low
1. Ensure that the tractor motor operates during power–on. If the motor is operating
properly, go to Step 6. Otherwise, go to Step 2.
2. Check the fuse.
a. Put the leads of the digital multimeter on either side of F2 (fuse 2) on the I/O
b. Measure the resistance, which should be 0Ω (the fuse is not blown).
If the fuse is blown, replace the I/O board.
3. Check the I/O board. Check whether the relay (RY2) and the tractor motor
operate during power–on. If the relay is not operating properly, replace the I/O
board after checking the output of the DC Power Supply board.
4. Check the tractor motor.
a. Put the positive lead of the digital multimeter on pin 1 of CN29 on the I/O
b. Place the rotary switch in the "E" position on the MPU board.
c. Power ON the printer.
d. After the paper moves forward and back, remove the tractor motor terminal
e. Measure the voltage, which should be about –10V.
If the tractor motor is not normal, replace it.
Troubleshooting
CHECKLIST: TRACTOR MOTOR
FUSE (F2)
I/O BOARD
TRACTOR MOTOR ENCODER (TME)
CONTROL CIRCUIT
board.
board, and the negative lead on the PG.
connector from the motor terminal.
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