Oki B 4100 Maintenance Manual page 252

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 WN5
Replace MCNT Board.
Signal route:
CN10-A6, B6 (R) IC12-3
IC8-60 (RXA1)
IC8-26 to 33 (AD0 to AD7)
Return to section 7.1.1
40055101TH Rev.4
A
RX (Receiver)
Yes
No
No
Yes
No
board?
Yes
Yes
RX End
Check the line.
Yes
Replace NCU Board.
Solved?
No
Replace MCNT Board.
Signal route:
CN1-3, 4 RL1-8, 5
T1-1, 3 T1-2, 6
CN3-19, 20 (R)
Possible cause:
CML signal
252 /