IBM 6400 series Maintenance Manual page 115

Adjust the right tractor so that it does not pull paper too tightly or leave it
too loose. The right tractor should hold the paper under "slight" tension.
3. Inspect the shuttle frame assembly for print chaff, debris, or ink residue that could
be causing the problem.
Clean the shuttle frame assembly.
4. Check the ribbon for folds or tears. Check that the ribbon guides are tight and the
ribbon tracks straight across them.
Rewind or install new ribbon. If the ribbon does not track straight across
the ribbon guides, adjust the ribbon guides. If the ribbon guides are
loose, tighten them. If the ribbon guides are damaged, replace them.
5. Power off the printer. Remove the shuttle cover. Remove the shuttle frame
assembly. Inspect the ribbon mask for bends or deformation that adversely affect
paper feeding. Make sure the hammer bank cover assembly is correctly installed
on its mounting pegs. Check the shuttle frame assembly for broken hammer
springs, hammer tips, or contaminations.
Replace any damaged hammer spring assemblies. Replace the hammer
bank cover assembly if it is deformed or damaged.
6. Check the platen gap.
Adjust the platen gap.
7. Remove the paper guide assembly or pedestal top cover. Make sure Connectors
P105 and P108 have good connections on the CMX controller board. Make sure
connectors P04 and P05 have good connections at the shuttle frame assembly.
Reseat connectors P04, P05, P105, and P108
8. Power on the printer.
If the problem still occurs, replace the shuttle frame assembly.
9. Power on the printer.
If the problem still occurs, replace the power supply board.
10. Power on the printer.
If the problem still occurs, replace the CMX controller board.
CLEAR JAM message instead of LOAD FORMS when printer is out of paper
1. Power off the printer. Remove the paper guide assembly or pedestal top cover.
Remove the barrier shield (cabinet model) or the barrier shield and paper guide
(pedestal model). Check that the paper detector switch assembly is securely
mounted in its bracket.
Troubleshooting 115