Brother International HL-1660E Service Manual - Page 81

Possible cause Step Check Result Remedy Development 10 Do the pins 3, 4 and 5 of the connector No Replace the scanner unit or input signal error P6 on the main PCB have the following value the harness. respectively when a sheet of paper is fed from the MP tray? P6-3 pin (DBAC) --- Change in voltage from 6V approx. to 0V just when a sheet of paper is fed from the registration unit. P6-4 pin (DBDC) --- Change in voltage from 9V approx. to 0V just when a sheet of paper is fed from the registration unit. P6-5 pin (DNSTY) --- Change in voltage to 2.5V just when a sheet of paper is fed. Dirt on power 11 Is there any dirt on the cartridge side supply terminal development terminal of the transfer unit and on the terminal of the high-voltage power Failure in the supply development unit? (is there continuity development between them?) high-voltage circuit No Clean the contacts to assure the continuity. Yes Replace the high-voltage power supply PCB assy. I-2 Dark Possible cause Step Check Result Remedy Density setting 1 Does printed image improve when density setting is changed on the control panel? Yes Adjust the proper setting on the control panel. EP-ED cartridge 2 Does printed image improve when the EP-ED cartridge is replaced? Yes Replace the EP-ED cartridge. Dirt on the grounding terminal Charging input signal error 3 Does printed image improve when continuity is improved by cleaning the EP-ED cartridge grounding terminal and the printer unit grounding terminal? Yes Clean the contacts to assure the continuity. 4 Do the pins 1, 2 and 5 of the connector P6 No Replace the main PCB assy on the main PCB have the following value or the harness. respectively when a sheet of paper is fed from the MP tray? P6-1 pin (HV1AC) --- Change in voltage from 6V approx. to 0V just when a sheet of paper is fed. P6-2 pin (HV1DC) --- Change in voltage from 9V approx. to 0V just when a sheet of paper is fed. P6-5 pin (DNSTY) --- Change in voltage to 2.5V just when a sheet of paper is fed. Dirt on power 5 Is there any dirt on the cartridge side charging No Clean the terminal to assure supply terminal terminal of the transfer unit and on the terminal the continuity. Failure in the charging high- of the high-voltage power supply charging unit? (is there continuity between them?) Yes Replace the high-voltage power supply PCB assy. voltage circuit VI - 5