Brother International MFC 8890DW Service Manual - Page 130

■ Ghost - Check the machine's environment, conditions such as high or low humidity may cause this situation to occur. - Check that the appropriate media type or size is selected in the printer driver. - Replace the drum unit with a new one. Step 1 2 Cause Check HVPS PCB failure Is the problem solved after replacing the HVPS PCB ASSY? Main PCB failure Is the problem solved after replacing the main PCB ASSY? Result Remedy Replace the HVPS PCB Yes ASSY. Replace the main PCB Yes ASSY. ■ Fogging - Replace the toner cartridge with a new one. - Replace the drum unit with a new one. - Do not use acid paper. - Check if there is dust or paper powder in the machine. Step 1 2 3 Cause Check Toner sensor failure (Machine body) Is the toner sensor performed normally by following the procedure in "4.10 Sensor Operational Check (Function code 32)" in Chapter 7. HVPS PCB failure Is the problem solved after replacing the HVPS PCB ASSY? Main PCB failure Is the problem solved after replacing the main PCB ASSY? Result Remedy Replace the toner sensor PCB unit ASSY and the toner LED PCB ASSY. No Replace the HVPS PCB Yes ASSY. Replace the main PCB Yes ASSY. CAUTION : • This problem often occurs when the drum unit or toner cartridge is nearly at the end of life. 3-58 Confidential