Brother MFC-B7720DN Service Manual

2-53
Confidential
 Error code 4F01
The new toner sensor of the toner cartridge could not detect a new cartridge properly.
<User Check>
• Replace the toner cartridge with a new toner cartridge again.
• If the machine is on the uneven surface, place it on a level surface.
 Error code 4F05
New process sensor could not detect the new drum unit correctly.
<User Check>
• Replace the drum unit with a new drum unit again.
• If the machine is on the uneven surface, place it on a level surface.
 Error code 5E00
New toner box sensor could not detect the new toner box correctly.
<User Check>
• Replace the toner box with a new toner box again.
• If the machine is on the uneven surface, place it on a level surface.
Step Cause Remedy
1
Connection failure of the new
toner sensor PCB harness
Reconnect the new toner sensor PCB
harness.
2
New toner actuator coming off or
caught in some sections of the
machine
Reattach the new toner actuator.
3 New toner sensor failure Replace the new toner sensor PCB ASSY.
4 Main PCB failure Replace the main PCB ASSY.
Step Cause Remedy
1
High-voltage power supply PCB
failure
Replace the high-voltage power supply
PCB ASSY.
2 Main PCB failure Replace the main PCB ASSY.
Step Cause Remedy
1
New toner box sensor failure Replace the high-voltage power supply
PCB ASSY.
2 Main PCB failure Replace the main PCB ASSY.

Brother MFC-B7720DN Specifications

General

Brand	Brother
Model	MFC-B7720DN
Category	All in One Printer
Language	English