IBM 6400 series Maintenance Manual page 121

Operator panel keys do not work
1. Power on the printer. Check the operation of the control panel keys.
Replace the control panel assembly.
2. Power on the printer. Check the operation of the control panel keys.
Replace the control panel cable assembly.
3. Power on the printer. Check the operation of the control panel keys.
Replace the CMX controller board.
Paper feeds poorly
1. Check the forms thickness lever: if it is set too tightly paper feeding can be
affected.
Set the forms thickness lever to match the thickness of the paper being
used.
2. Power off the printer. Remove paper. Inspect the paper feed path for obstructions
that could snag paper.
Clear paper feed path of any obstructions.
3. Inspect the tractors and tractor door springs for damage or excessive wear.
If either tractor is damaged or excessively worn, replace both tractor
assemblies.
4. Check the paper feed motor pulley for looseness.
Hold the collar snug against the motor pulley and torque the 7/64 inch
setscrew to 25
5. Check the condition and tension of the paper feed timing belt.
Adjust the paper feed timing belt. Replace the belt if it is damaged.
6. Check the platen gap.
Adjust the platen gap.
7. Remove the paper guide assembly or pedestal top cover. Make sure connector
P107/PAPR M is fully seated in connector J107 on the CMX controller board.
Connect P107/PAPR M to J107 on the CMX controller board.
8. Power on the printer. Load paper. Press Form Feed and View several times and
check that paper moves in both directions.
Troubleshooting
2 inch-pounds (2.82 0.23 N m).
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