Brother HL-3040CN Service Manual page 90

Error code 78
Print Unable 78
Turn the power off and then back on again.
Fuser unit error (The center thermistor detects rapid temperature falling.)
Step
1 Harness connection failure
between fuser unit connector and
eject front sensor PCB ASSY
2 Harness connection failure
between eject front sensor PCB
ASSY and main PCB ASSY
3 Fuser unit failure
4 Low-voltage power supply PCB
failure
5 Eject front sensor PCB failure
6 Main PCB failure
■ Error code 5B
Short paper
Open the Back Cover and then press Go.
Paper of which size is not supported is used. (Paper of less than 148 mm length is fed.)
< >
User Check
- Open the back cover and remove the paper.
■ Error code 5C
Small paper
Open the Back Cover and then press Go.
Paper of which size is not supported is used.
(Paper of less than 148 mm length is specified from a computer.)
< >
User Check
- Open the back cover and make print, or change the paper specified from a computer to
larger-size paper.
■ Error code 5D
Belt End Soon
The belt unit will reach the end of life soon. (The belt unit counter value reaches 90 % of life.)
< >
User Check
- Prepare a new belt unit.
Cause
3-26
Remedy
Check the harness connection between
the fuser unit connector and eject front
sensor PCB ASSY, and reconnect it.
Check the harness connection between
the eject front sensor PCB ASSY and
main PCB ASSY, and reconnect it.
Replace the fuser unit.
Replace the low-voltage power supply
PCB ASSY.
Replace the eject front sensor PCB ASSY.
Replace the main PCB ASSY.
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