Brother DCP 8040 - B/W Laser - All-in-One Service Manual page 235

CHAPTER 6 TROUBLESHOOTING
F-4 No bell ring.
Possible cause
Ring delay
Ring volume
Connection
between main
PCB and NCU
PCB
Harness
between main
PCB and NCU
PCB
Speaker
Relay PCB
NCU PCB
Main PCB
Step Check
Ring delay is set to "0".
1
Ring volume is set to "OFF".
2
Main PCB and NCU PCB are
3
properly connected.
Harness wire is damaged.
4
Replacement of speaker
5
solves the problem.
Replacement of relay PCB
6
solves the problem.
Replacement of NCU PCB
7
solves the problem.
Replacement of main PCB
8
solves the problem.
Result
Yes
Yes
No
Yes
Yes
Yes
Yes
Yes
6-32
Remedy
Set the ring delay to other
than "0".
Set the ring volume to other
than "OFF".
Fix the connection properly.
Replace the harness with a
normal part.
Replace the speaker with a
normal part.
Replace the relay PCB with a
normal part.
Replace the NCU PCB with
a normal part.
Replace the main PCB with
a normal part.