IBM 6400-I15 Maintenance Manual - Page 84

7. Run a print test. If the message appears, replace the CMX controller board. Record the message and return it with the defective board. 058 SHUTTLE JAM SEE USER'S GUIDE 1. The shuttle is not moving or is moving at the wrong speed. Check the forms thickness lever: if it is set too tightly, it can slow the shuttle enough to trigger the fault message. Set the forms thickness lever to match the thickness of paper and provide satisfactory print quality, but not too tightly. 2. Check the platen gap. Adjust the platen gap. 3. Inspect the ribbon mask for bends or deformation that snag and interfere with shuttle movement. Make sure the hammer bank cover assembly is correctly installed on its mounting pegs. Reinstall the hammer bank cover assembly. Replace a damaged or deformed hammer bank cover assembly. 4. Run a print test. If the message appears, power off the printer. 5. Remove the shuttle cover. Remove the paper guide assembly or the pedestal top cover. Inspect the shuttle mechanism for obstructions. Check that all cables are attached at the shuttle and the CMX controller board. Make sure the MPU cable is not pinched. (Refer to Appendix A, Interconnection Diagram, page 295.) Remove obstructions and reseat all cables. Check the resistance of MPU in P107. (Refer to the Main Wire Test Tables, page 297.) Replace the MPU if it fails the test. 6. Run a shuttle test and observe shuttle movement. If the shuttle oscillates too slowly, adjust the gap between the MPU assembly and the flywheel to 0.010 ± .001 inch (0.254 ± 0.025 mm). Torque the 7/16 inch MPU clamp screw to 18 ± 1 inch-pounds (2.03 ± 0.11 NSm). 7. Run a print test. If the message appears, replace the MPU and the MPU cable assembly. 8. Run a print test. 84 Troubleshooting