HP Color LaserJet 8500 Service Manual - Page 471

2,000-sheet input unit troubleshooting This section provides a systematic approach to identifying the causes of malfunctions and errors in the 2,000-sheet input unit. Ways to troubleshoot the unit In general, there are three possible sources of malfunction:
the 2,000-sheet input unit itself
printer electronics
the C-link cable that connects the unit and the printer Begin troubleshooting 1 Print or display the error log. Evaluate the error log for any specific error trends in the last 10,000 printed pages. 2 Print a configuration page to verify the proper installation of the paper-handling accessories. • If any of the installed accessories are not shown on the configuration page, check the corresponding cable connections. • Verify that the C-link cable is correctly connected and functional. • Verify that DC power is available to the paper-handling accessories. 3 If necessary, use one of the following diagnostic tools to isolate the problem: • Status LED on the front of the unit-Indicates the status of the unit (see page 470). • Service LED inside the back cover-The pattern of flashing (long and short) isolates the problem (see page 471). • Standalone running test-Tests whether the unit itself is functioning properly (see page 473). • Motor test-Checks the motor to see if it is working properly (see page 474). • Sensor tests-Checks the sensors to see if they are working properly (see page 475). EN 2,000-sheet input unit troubleshooting 469