Brother MFC4820C Service Manual page 189

Trouble
(4) Light
(5) Dark
(6) Black or blurred vertical
stripes
At the scanner
Check the following components:
- CIS unit
- Main PCB
At the printer
Check the following components:
- Ink cartridges
- Print head unit
- Main PCB
- Power supply PCB
- Print head parameters stored in the EEPROM on the driver
PCB (Refer to Chapter 7, Section 7.5.15 "Updating of
Property Data.")
At the scanner
Check the following components:
- CIS unit
- Main PCB
At the printer side
• For each of the four ink colors, perform the head purging
operation several times to remove dust or air bubbles from its
nozzles. If the problem persists, replace the print head unit.
• Check the paper feed-related rollers.
• Replace the main PCB and power supply PCB.
At the scanner
Check the following components:
- CIS unit
- Scanner glass
At the printer side
• Check whether paper is in abnormal contact with any other
components during ejecting.
• Check the CR encoder strip for stains or scratches. (If the CR
encoder strip is not hooked properly, correct it.)
8 -1 8
Action to be taken