Brother International HL-1660E Service Manual - Page 80

3.2 Troubleshooting Image Defects I-1 Light Possible cause Step Check Result Remedy Toner shortage 1 Does printed image improve when the EP-ED Yes Replace EP-ED cartridge. cartridge is replaced? ECONOMY mode 2 Is the ECONOMY mode active? Yes Cancel the ECONOMY mode. Printing density setting - 3 Does printed image improve when printed density setting is changed on the control panel ? Yes Adjust the proper setting on the control panel. 4 During a printing, open the toner cartridge lid Yes Go to the Step 9. in the printer and pull out the EP-ED cartridge. Open the drum shutter of the EP-ED cartridge and check the toner image on the drum. Is the toner image before transfer is light? Paper failure Transfer roller failure Transfer input signal error 5 Does the print quality improve when fresh paper is used? Yes Use recommended paper. 6 Does the print quality improve when print is made with transfer roller changed? Yes Clean the transfer roller [Use dry lint-free paper (producing little paper dust) to clean the transfer roller. Never use solvents] and, if dirts subsist, replace the transfer roller assy. 7 Do the pins 7 and 8 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? P6-7 pin (HVT2) --- Change in voltage from 15V approx. to 0V about 1 second after paper feeding. P6-8 pin (HVT3) --- Change in voltage from 9V approx. to 0V just when the voltage at the 7 pin changes from 0V to 15V. Dirt on power 8 Clean the transfer roller right end bearing, the No Clean the contact to assure supply terminal check continuity between the transfer roller the continuity. Failure in the transfer high- power supply spring and the terminal of the high-voltage transfer unit. Is there continuity? Yes Replace the high-voltage power supply assy. voltage circuit Insufficient LD light 9 Does print quality improve when the scanner unit is improved? Yes Replace the scanner unit or the harness. Continued to the following page VI - 4