Diagnostics information 2-23Cooling fan service checkCover interlock switch service checkNote: Make sure a print cartridge assembly is installed and the cover closes all the way, engaging the coveropen switch lever.LVPS/HVPS Verify main power to controller boardWith the printer off, unplug the LPS/HVPS cable at J502 on the controller board. Verifygrounds on pins 10, 12, 14, 16 and 18 for both the cable and the controller board. If any ofthese grounds are incorrect, then check the cable for continuity. If the cable fails continuity,then call the next level of support.Turn the printer on with the cable still unplugged, and verify the following on the cable(controller board will not be powered):If any of the voltages are incorrect, then replace the LVPS/HVPS. See “Dead machineservice check” on page 2-24.FRU ActionCooling fan Make sure the fan cable plug is properly seated at J9 (controller board).Turn the printer on. Within a few seconds, the controller board assembly should apply+24 V dc to pin 2.• If voltage is not present, then check or replace the controller board. See “Controllerboard removal” on page 4-6.• If voltage is present, then check pin 1 for 24 V dc as well. If it is close to 24 V dc whilethe fan is still idle, then replace the fan. See “Fan removal” on page 4-16.FRU ActionCover interlock switch Disconnect the cover interlock cable from the controller board at J7.With the printer turned off:1. Verify continuity between cable pin 1 and pin 2 with the door closed and discontinuitywith the door open.2. Verify continuity between cable pin 1 and pin 3 with the door open and discontinuity withthe door closed.3. Verify discontinuity between cable pins 2 and 3 whether the door is open or closed.• If any fail, then replace the cover interlock switch.• If both pass continuity, then turn the printer on, and measure +5 V dc on pin 2 at J7 onthe controller board.• Verify pin 3 at J7 is ground.• If voltage or ground is not present, then see “Controller board service check” onpage 2-22 for more information.Controller board service check (Continued)FRU ActionPins Voltage6, 17, 19 +24 V dc1, 3-5, 11, 13,15 +5 V dc
