Xerox Phaser 7700 Service Manual page 77

Error Chain /
Code Link
20 09-342 ERROR 20 TRANSFER ROLLER CONTACT FAILURE
Enter Service Diagnostics Mode.
Perform the "2nd BTR Motor" test. Listen for a short run of the motor.
Did the motor run?
Yes No
Remove the Left-Hand Rear Mid Cover (RRP 5, on page 7-144).
Inspect the Left-Hand Cover Assembly wiring harness for damage and ensure all
connectors are properly seated.
If the problem persists, replace the Engine Control Board (RRP 42, on page 7-190).
If the problem continues to persist, replace the entire Left-Hand Cover Assembly
(RRP 6, on page 7-146).
Remove the Rear Cover (RRP 1, on page 7-140) and Rear Shield (RRP 9, on page 7-149).
Reconnect power and enter Service Diagnostics Mode.
Measure the voltage at the Engine Control Interface Board P532A-14 (see figure page 3-47).
Perform the "2nd BTR Motor" several times.
Does the voltage toggle between +5 VDC and 0 VDC when the test is run?
Yes No
Replace the Transfer Roller Retract Sensor.
Replace the Engine Control Board (RRP 42, on page 7-190).
21 09-343 ERROR 21 TRANSFER ROLLER RETRACT FAILURE
Enter Service Diagnostics Mode.
Perform the "2nd BTR Motor" test. Listen for a short run of the motor.
Did the motor run?
Yes No
Remove the Left-Hand Rear Mid Cover(RRP 5, on page 7-144).
Inspect the Left-Hand Cover Assembly wiring harness for damage and ensure all
connectors are properly seated.
If the problem persists, replace the Engine Control Board (RRP 42, on page 7-190).
If the problem continues to persist, replace the entire Left-Hand Cover Assembly
(RRP 6, on page 7-146).
Remove the Rear Cover (RRP 1, on page 7-140) and Rear Shield (RRP 9, on page 7-149).
Reconnect power and enter Service Diagnostics Mode.
Measure the voltage at the Engine Control Interface Board P532A-14 (see figure page 3-47).
Perform the "2nd BTR Motor" several times.
Does the voltage toggle between +5 VDC and 0 VDC when the test is run?
Yes No
Replace the Transfer Roller Retract Sensor.
Replace the Engine Control Board (RRP 42, on page 7-190).
2-54
Phaser 7700 Color Printer
Front Panel Message