Brother MFC-8220 - Page 208

CHAPTER 6 TROUBLESHOOTING
6-30
F-7
No dial tone
Possible cause Step Check Result Remedy
Connection
between main
PCB and NCU
PCB
1
Main PCB and NCU PCB are
properly connected.
No Fix the connection properly.
Harness
between main
PCB and NCU
PCB
2
Harness wire is damaged. Yes Replace the harness with a
normal part.
NCU PCB 3
Replacement of NCU PCB
solves the problem.
Yes Replace the NCU PCB with
a normal part.
Main PCB 4
Replacement of main PCB
solves the problem.
Yes Replace the main PCB with
a normal part.