Xerox 8500DN Service Manual - Page 193

General Troubleshooting n. If the Electronics Module, I/O Board and Control Panel are working, the error code 34,001.43 should appear on the display to indicate the Printhead is disconnected. If the correct error code is displayed, continue with the next steps of the procedure. If the correct error code is not displayed, replace the Control Panel and I/O Board and verify the correct error code appears. Retest Electronics Module, I/O board, Control Panel combination. If no error code displays, return the original Control Panel and I/O Board to the printer. Replace the Electronics Module and then continue with the next steps of the procedure. o. If a different error code is displayed, see the "Fault Code Error Message Troubleshooting" on page 3-7 for a definition of the problem and the procedures needed to solve the problem. 2. Repeat these procedures to check all circuits connected to the I/O Board: a. Turn off printer and wait 30 seconds for power supply capacitors to discharge. b. Plug in the I/O Board connectors, one at a time, and perform steps C and D for each connector. c. Turn on printer and wait for the error code 34,001.43. Check that the three voltage indication LEDs inside the Electronics Module (visible through the vent holes of the Electronics Module near the AC power switch) are lit. d. If the proper error code and LED doesn't appear after each I/O connector is reconnected, repair or replace the faulty circuit. e. If the proper code appears, repeat the procedures until all I/O board connectors are plugged back in. f. If repairs are made during this step, plug in all connectors to printer and retest. If printer is fixed, reattach covers to printer and perform a full test. If no defects are found in this step, continue with next step. 3. The proper error code is displayed, repeat the following procedures to check all circuits connected to the Electronics Module: a. Turn off printer and wait 30 seconds for power supply capacitors to discharge. b. Plug in the connectors, one at a time, and perform steps C and D for each connector. c. Turn on printer and wait for the error code 34,001.43. Check that the three voltage indication LEDs inside the Electronics Module (visible through the vent holes of the Electronics Module near the AC power switch) are lit. d. If the proper error code and LED doesn't appear after each I/O connector is reconnected, repair or replace the faulty circuit. e. If the proper code appears, repeat the procedures until all I/O board connectors are plugged back in. f. If repairs are made during this step, plug in all connectors to printer and retest. If printer is fixed, reattach covers to printer and perform a full test. If no defects are found in this step, replace Electronics Module, test printer, reattach covers to printer and perform a full test. Verifying Print Engine Operation by Printing Stored Pages 1. Turn On the printer. If the printer does not begin initializing, go to the topic, "Measuring AC Power Supply Voltages" on page 4-64. 2. Once the Power light is on (not blinking) and the Control Panel displays Ready to Print it is now possible to print a stored page. 3. If a page prints, the print engine is working correctly. If not, a problem exists with the print engine. Phaser 8400/8500/8550/8560 Color Printer Service Manual 4-63