HP 8000dn Service Manual - Page 443

CAUTION 2 x 500-sheet Input Tray Motor Test This test verifies that the three motors on the 2 x 500-sheet Input Tray are functioning properly. 1 Identify the Back Cover (opposite side from tray door). Remove the 4 screws in the Back Cover. Remove the Back Cover. 2 Pull open Trays 4 and 5, and open the Vertical Transfer Unit (VTU). 3 Set the DIP switches on the Controller PCA to Motor Test Mode. (See table 7-26 on page 418 for an explanation of the DIP switch settings.) 4 To turn the power supply switch to Diagnostic Mode, pull out on the blue handle. • If the motors are working properly, you will hear them as they rotate continuously. • If the motors do not rotate, replace the corresponding field-replaceable unit: either the Paper Pickup Assembly, the VTU, or the Paper Deck Drive Assembly. 5 To stop the test, set the power supply switch back to Operational Mode (push in), and reset the DIP switches on the Controller PCA to the off position (see table 7-26 on page 418). 2 x 500-sheet Input Tray Standalone Running Test This test verifies that the 2 x 500-sheet Input Tray is functioning properly. For this test, use the LED located on the Controller PCA. (See table 7-27 on page 421 for an interpretation of the LED patterns.) If the 2 x 500-sheet Input Tray is underneath the printer, paper jams may occur because the printer will not pick up the paper. To prevent excessive paper jams during this test, feed only 6 to 8 pages. 1 Make sure that there is paper in both trays. 2 Set the DIP switches on the Controller PCA for standalone running mode (see table 7-26 on page 418 for an explanation of the settings). 3 To test Tray 5, open Tray 4. EN Diagnostics on Accessories 419