01/026-178825/8830 Printer Transfer and Developer Bias Voltages incorrectGeneral ProceduresTransfer and Developer Bias Voltages incorrect (Tag 19)PROBLEMTransfer and developer voltages are set incorrectly.CAUSELate in the program it was determined that the developer bias should be set at -420 VDC andtransfer should be set at .6 ma DC . Inadvertently the change was never cut in on the manu-facturing line. The current settings can cause intermittent broken black lines or backgroundbands in the process direction.SOLUTIONPLEASE MAKE THE FOLLOWING ADJUSTMENT CHANGES TO THE printer ON THENEXT SERVICE CALL:1. ADJUST the Transfer output to “+ 0.6 VDC”Go to GP 1 HVPS Checkout in this section. Locate the Transfer potentiometer (“TRF I”)nearest the center of the HVPS (closest to the transfer output transformer module). Care-fully remove the RTV. Using the 26V return on the HVPS as the common and the “TFRI” test point, adjust the potentiometer to obtain “+ 0.6 +/- 0.1 VDC” during a print.Mark appropriate change in manual (Table 1 on page 6-10).CHANGE the Developer Bias default -Enter diagnostic mode - Go to . Input diagnostic test code 84. ENTER 1E (E is obtained byholding down the period(.) button and striking the “4” button). ENTER Message: chain 84;address 01E is 4E. Using the “Previous Button” scroll down six (6) times or until the displayreads chain 84; address 01E is 48.ENTEREXITEXAMINE Developer bias output level - Go to GP 1 HVPS Checkout in Section 6 of thismanual; . Using the 26V return on the HVPS as the common and the “DEV V” test point. Inthe print mode the output should be “(-) 4.20 +/- 0.05 VDC”. Mark appropriate change inmanual (Table 1 on page 6-10).Mark off TAG 19 on the TAG matrixOnce these adjustments are made you may see a slight increase in toner consumption. Thebenefits of doing these adjustments are:1. Increase “Cleaning Field” latitude• Reduced occurrence of background bands in the process direction.• Reduced occurrence of intermittent broken black lines in the process direction.2. Provides additional lubrication for the cleaning blade.CAUTIONThe tolerance window for electrostatics on the printer is very narrow. This printer must be setto specifications using the electrometer to ensure proper performance. If electrostatics are setincorrectly the printer will exhibit print quality problems, excessive dirt levels, and increasedtoner consumption.REQUIREMENTS FOR FIELD RESOLUTION• DOCUMENTATION N/A• TAG 19• PART NUMBERS N/A• CUT IN SERIAL NUMBER N/A
