Brother International HL 1240 Service Manual - Page 148

CHAPTER 6 TROUBLESHOOTING I-20 Downward fogging of solid black Possible cause Toner cartridge failure High-voltage power supply PCB failure Step Check 1 Is the problem solved after replacing the toner cartridge? 2 Is the problem solved after replacing the high-voltage power supply PCB? Result Remedy Yes Replace the toner cartridge. Yes Replace the high-voltage power supply PCB. I-21 Horizontal lines Possible cause Paper feed roller Paper cassette contacts Step 1 2 Check Are the feed roller shaft and the ground contact connected correctly? Are the ground contacts on the back side of the paper cassette connecting correctly? Result Remedy No Check the connection between the shaft and the ground contact. Also check the ground contact on the back of the feed roller. Refer to P.4-24. No Clean the contacts. Ground contacts ➆ 6-38