IBM 6400 series Maintenance Manual page 93

6. Power on the printer. Run an Operator Print Test. (See page 135.)
If the ribbon a RIBBON STALL message appears, replace the CMX
controller board. Record the message and return it with the defective
board.
090 SHUTTLE COVER OPEN
CLOSE SHUTTLE COVER
1. The shuttle cover is missing, damaged, or not correctly installed. Inspect shuttle
cover for warping, damage, or missing magnet. (The magnet covers the sensor
housing when the cover is installed.)
If the shuttle cover is warped, damaged, or the magnet is missing,
replace the shuttle cover assembly.
2. Check shuttle cover installation.
Install the shuttle cover correctly. Make sure the cover lies flat and the
two captive screws are fully seated.
3. Power on the printer.
If the message appears, power off the printer. Remove the paper guide
assembly or pedestal top cover. Disconnect P107 on the CMX controller
board and check the CVO switch by testing for continuity across pins 18
and 20. (Refer to the Main Wire Test Tables, page 297.) Replace the
cover open switch assembly, as required.
4. Power on the printer.
If the message appears, replace the CMX controller board. Record the
message and return it with the defective board.
092 RIBBON DRIVER CIRCUIT
1. The CMX controller board does not detect a ribbon drive motor.
Cycle power. If the message appears, power off the printer. Remove the
paper guide assembly or pedestal top cover. Reseat the cable
connections of both ribbon drive motors.
2. Power on the printer. Using a screwdriver, short across the ribbon guide screws
to reverse ribbon hub motion. Check for a ribbon drive motor that will not wind the
ribbon.
If the ribbon will not wind in one or both directions, replace the defective
ribbon drive motor(s). If the ribbon winds in both directions, replace the
CMX controller board. Record the message and return it with the
defective board.
Troubleshooting 93