IBM 6400 series Maintenance Manual page 81

6. Inspect the ribbon mask for bends or deformation that block the paper path or
prevent paper from exiting the pedestal top cover.
Replace a damaged hammer bank cover assembly.
7. Check the condition and tension of the platen open belt.
Adjust the platen open belt. Replace the belt if it is damaged.
8. 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.
9. Inspect the tractors and tractor door springs for damage or excessive wear.
If either tractor is worn or damaged, replace both tractor assemblies.
10. Check the condition and tension of the paper feed belt.
Adjust the paper feed belt. Replace the belt if it is damaged.
11. Check the platen gap.
Adjust the platen gap.
12. Clean the paper motion detector with a cotton swab and alcohol. At the control
panel, set the paper motion detector (PMD) fault setting to DISABLE. Load paper.
Run a print test and observe how the paper feeds.
If the message appears, replace the CMX controller board. Record the
message and return it with the defective board. If the message does not
appear, replace the paper detector switch assembly and set the paper
motion detector (PMD) to ENABLE.
041 BUFFER OVERFLOW
1. The print buffer has overflowed on a serial interface. The printed output may
contain random * (asterisk) characters. Make a configuration printout. Verify that
the printer matches the host serial interface configuration settings for Data
Protocol, Baud Rate, Data Bits, Stop Bits, Parity, Data Terminal Ready, and
Request to Send.
Set printer serial interface parameters to match those of the host.
2. Send a print job to the printer.
If the message appears, go to Communications Failures, page 133.
Troubleshooting
2 inch-pounds (1.02 0.23 N m). Tighten
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