45762101TH Rev.1 
2-37
2. TROUBLESHOOTING PROCEDURES
2.5.5.(2) Abnormal MFP operation after powered on
(2-1) No operation
Check item Checking Action in case of fail
(2-1-1) Checking power supplies
AC power supplied to the 
printer
Check the supplied voltage from 
the AC power source.
Supply AC power.
5V and 24V power supplied to 
CU/PU board (MRM)
Check the power supply using 
the POWER connector on the 
CU/PU board (MRM). 
7, 8, 9pin: 24V 
1, 2, 3pin: 5V 
4, 5, 6pin: 0VL 
10, 11, 12pin: 0VP
Replace the low-voltage 
power supply.
5V, and 24V power supplied 
to SU board (MSU)
Check the power supply using 
the POWER connector on the SU 
board (MSU). 
3, 4pin: 5V 
7, 8pin: 24V 
5, 6pin: 0VL 
9, 10pin: 0VP
Replace the low-voltage 
power supply.
3.3V power supplied to SU 
board (MSU)
Check the power supply using 
the GDIIF connector on the SU 
board (MSU). 
3pin: 3.3V 
4, 6, 9pin: 0V
Replace the CU/PU 
board (MRM).
(1-2) Display of OKI logo
Check item Checking Action in case of fail
(1-2-1) Operation panel display does not change.
Operation panel display OKI logo stays on. Replace the CU board 
(MRM).
(1-3) Error message display
Check item Checking Action in case of fail
(1-3-1) Error message
Error message display Check the detail of the error on 
the error message list.
Follow the instructions.