IBM 6400 series Maintenance Manual page 83

If any socket pins are bent or damaged, replace the CMX controller
board.
2. Install the flash and DRAM SIMMs, making sure they are fully and correctly
seated. Power on the printer. Download the emulation.
If the message appears, replace the flash SIMM(s).
3. Power on the printer. Download the emulation.
If the message appears, replace the DRAM SIMM(s).
4. Power on the printer. Download the emulation.
If the message appears, replace the CMX controller board. Record the
message and return it with the defective board.
057 CLOSE PLATEN
1. The forms thickness lever is open.
Load paper. Close the forms thickness lever.
2. Power off the printer. Remove the paper guide assembly or pedestal top cover.
Disconnect connector P107 from the CMX controller board. Check continuity of
the platen interlock switch cable from P107/PLO to the switch.
Replace the platen interlock switch assembly if it fails the continuity test.
(Refer to Appendix A, Switch Assembly, Platen Interlock.)
3. Check that the platen interlock switch is not loose.
Tighten the screws securing the platen interlock switch
4. Check the condition and tension of the platen open belt.
Adjust the platen open belt. Replace the belt if it is damaged.
5. Check the platen open pulley and the platen pulley for looseness.
Bottom out the platen open motor pulley on the motor shaft and torque
the 1/16 inch set screw to 9
the 7/64 inch setscrew in the platen shaft pulley, then open and close the
forms thickness lever and check that the platen pulley setscrew does not
hit the left ribbon guide.
6. Disconnect connector P106 from the CMX controller board. Check the resistance
of connector P106/PLAT M. (Refer to the Main Wire Harness Test Tables on page
297.)
Replace the platen open motor if it fails the resistance test.
Troubleshooting
2 inch-pounds (1.02 0.23 N m). Tighten
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