Service manual

MFC-8420/8820D/8820DN, DCP-8020/8025D/8025DN
SERVICE MANUAL
6-27
M-12 Engine PCB error
Possible cause Step Check Result Remedy
Fixing unit
ground wire
connection
1 Is the ground wire on the fixing
unit secured with the shoulder
screw correctly?
No Secure the ground wire
correctly with the shoulder
screw.
Harness
connection
failure
2 Is the connection of the
connector between the main
PCB and the engine PCB
connected correctly?
No Reconnect the connectors
securely.
Engine PCB 3 Is the problem solved by
replacing the engine PCB?
Yes Replace the engine PCB.
Main PCB 4 Is the problem solved by
replacing the main PCB?
Yes Replace the main PCB.
M-14 DIMM failure
Possible cause Step Check Result Remedy
DIMM failure 1 Try installing DIMM into
another machine, then check
the memory size in Print
Settings.
Yes Replace the main PCB.
Is it possible to print the data? No Replace the DIMM.