Diagnostics information 2-31Black pageNote: Incorrect laser exposure or incorrect charging of the photoconductor causes an all black page. Alwaysverify the same results from a different print cartridge assembly and developer before proceeding.Heavy backgroundPoor development or poorly charged toner particles cause excessive background. This is more noticeable asthe toner cartridge nears end-of-life.FRU ActionToner electrodes (nota FRU) Check the three rearward electrodes below the toner cartridge assembly for contamination,damage, or a short to ground. Correct as necessary.Check continuity between the cable (DEV, TAR, and doctor blade) connection PCN3 andon the contact tips below the toner cartridge assembly.• If continuity fails, then call the next level of service.LVPS/HVPS boardController boardMiscellaneous cablesWith the printer off, disconnect the LVPS/HVPS cable from J502 on the controller board.Turn the printer on, and verify +24 V dc on pins 17 and 19 of the cable.Verify +5 V dc on pins 1, 3, 5, 13, and 15.Verify ground on pins 10, 12,14, 16, and 18.• If any of the values are incorrect, then replace LVPS/HVPS board.• If the grounds are incorrect, then check ground paths.• Check continuity in the cable. If the cable is bad, then call the next level of support.• If the values are correct and the toner electrodes are good, then replace the controllerboard.• See the “LVPS/HVPS service check” on page 2-25 and the “Controller boardservice check” on page 2-22, if necessary.FRU ActionToner cartridge (not aFRU)PC Kit (not a FRU)Check the toner darkness setting in the driver. Try a lower setting.Make sure the toner cartridge and PC Kit are correctly installed and the high voltagecontacts are clean.If the toner cartridge and PC Kit are installed correctly, then try a new PC Kit first and thentoner cartridge.LVPS/HVPSController boardCheck the contacts for correct installation and contamination where contact is madebetween the print cartridge assembly and spring contacts which connect to the LVPS/HVPSboard at CN203. Clean as necessary.If this does not correct the problem, then replace the following FRUs one at a time in theorder shown:• LVPS/HVPS board (See “Black page” on page 2-31 for pin values.)• Controller board
