Brother HL-1850 Service Manual page 234

CHAPTER 6 TROUBLESHOOTING
I-18 Gray background
Possible cause
Print paper
Toner sensing
failure
(printer side)
Toner cartridge
failure
Drum unit failure
NOTE:
The following cases increase the possibility of this problem.
• Acid paper is being used.
• The drum unit is at the end of its life.
• There is dust or paper powder.
Step Check
1 Does the paper being used
meet the paper specification
(weight, etc.).
2 Does the "Ready" message
appear on the LCD display
even after removing the drum
unit and toner cartridge?
3 Is the problem solved after
replacing the toner cartridge?
4 Is the problem solved after
replacing the drum unit?
Result
No Recommend to use the
specified types of paper.
Yes Recommend to change to
freshly unpacked paper.
Yes Toner sensor failure. Clean the
toner sensor and check the
toner sensor connection.
Yes Replace the toner cartridge.
Yes Replace the drum unit.
No Replace the high-voltage power
supply PCB.
6-50
Remedy