44015503TH  Rev. 1 
209 /
Oki  Data  CONFIDENTIAL
7.  TROUBLESHOOTING PROCEDURE
7.5.2.(18)  Humidity sensor error (error code 123)
(18-1)  Humidity sensor error
Check item Check work
Action to be taken 
at NG
(18-1-1) Check the system connection
Connection between 
the PU board and 
Operator Panel
 Chec
k if the 10-conductor FFC is connected to 
the OPE connector   of the PU board normally 
or not. 
Check if the 10-conductor FFC is connected 
to the CN1 connector   of the Operator Panel 
board normally or not. 
Check if the connector is connected in the half-
way only or not, and check if the connector is 
inserted in a slanted angle or not.
Re-connect the 
cable normally.
 FFC connecting 
the PU board and 
the Operator Panel 
board 
Check for open-circuit with VOM. 
Check that peeling off of sheath does not occur 
in any cables by visual inspection.
Replace the 
FFC with the 
normal FFC.
Check item Check work
Action to be taken 
at NG
(18-1-2) Environment condition
Sharp change 
of environment 
condition
Is the environment condition changed sharply 
from a low temperature environment to a high 
environment condition within a short time? 
(Example is such a case that a printer is moved 
from storage condition of a cold area in winter to 
an office environment.)
Leave a printer 
for around one 
hour in the new 
environment 
to get used 
to the new 
environment. 
After that, turn 
on the power 
again. 
Before turn 
on the power, 
touch the metal 
panel of the 
controller panel 
and the metal 
plate inside a 
printer to feel 
temperature 
increase 
inside a printer 
with human 
hands. After 
confirmation 
that the printer 
temperature has 
increased close 
to the room 
temperature, 
turn on the 
power again.