Oki OKIFAX 5400 Maintenance Manual page 207

The error counter of LCD
stops counting up?
Receive signal appears
across L1 and L2?
Receive signal appears
across CN3-19, 20 (R) and
CN3-7 (GND) of NCU
board?
Replace MCNT Board.
Signal route:
CN6-A6, B6 (R)→IC12-3→
IC8-60 (RXA1)→
IC8-26 to 33 (AD0 to AD7)
Return to section 7.1
40838301TH Rev.1
A
RX (Receiver)
Yes
No
No
Yes
No
Yes
Yes
Replace MCNT Board.
RX End
Check the line.
Yes
Replace NCU Board.
Solved?
No
7 - 17
Signal route:
CN1-3, 4→RL1-8, 5→
T1-1, 3→T1-2, 6→
CN3-19, 20 (R)
Possible cause:
CML signal