Oki MC770 series Maintenance Manual - page 161

45376001TH  Rev.1 

160 /

Oki  Data  CONFIDENTIAL

7. Troubleshooting and repair procedure

System Spec.

Code

Category

Cause

Error details

Measure

E728

Error

ADF document 

jam

Detection of chattering of a sensor 

– Chattering of a sensor is detected. 

Once a sensor becomes active, the 

sensor becomes inactive in 5mm 

feeding of the document. Then the 

inactive sensor becomes active in 

the next 5mm feeding. (Simplex and 

Duplex) 

Open the ADF cover, 

remove every jammed 

document from the paper 

feed path, and close the 

ADF cover. 

E741

Error

ADF

document jam

Reverse paper sensor stuck jam/

detection of out-of-spec oversized 

documents – The reverse paper sensor 

does not become inactive when the 

document is transferred to the distance 

exceeding the maximum page size. 

(Duplex) 

Open the ADF cover, 

remove every jammed 

document from the paper 

feed path, and close the 

ADF cover. 

E742

Error

ADF 

document jam

Detection of out-of-spec undersized 

documents – The reverse paper sensor 

becomes inactive before the document 

is transferred by the distance equal to 

the minimum page size. (Duplex) 

Open the ADF cover, 

remove every jammed 

document from the paper 

feed path, and close the 

ADF cover. 

E743

Error

ADF document 

jam

Non-arrival at the regist paper sensor at 

reversing to the front – After reversing 

to the front, the regist paper sensor 

does not become active in a lapse of a 

certain period of time. (Duplex) 

Open the ADF cover, 

remove every jammed 

document from the paper 

feed path, and close the 

ADF cover. 

E744

Error

ADF document 

jam

Non-arrival at the regist paper sensor 

at reversing to the back – When the 

document is transferred following 

reversal to the back, the regist paper 

sensor does not become active. 

(Duplex) 

Open the ADF cover, 

remove every jammed 

document from the paper 

feed path, and close the 

ADF cover. 

E870

Error

ADF document 

jam

ADF open jam – A document jam is 

caused by opening of the ADF while 

the RADF is operating. 

Remove every jammed 

document from the paper 

feed path, and close the 

ADF cover.

C260 ServiceCall

Scanner lamp 

error

Lamp error – Exposure adjustment has 

failed. 

Power cycle the unit. 

If the power cycle does not 

work to recover from the 

error, the unit needs repair.

The CIS may be damaged.

C270 ServiceCall

Scanner home 

position error 

The home position sensor does not 

become inactive in the designated 

period of time – The carriage does not 

move from the home position in the 

designated period of time. 

Power cycle the unit.

If the power cycle does not 

work to recover from the 

error, the unit needs repair.

The possible cause is 

the damage of the home 

position sensor, the belt 

that moves CIS, or the FB 

motor.

System Spec.

Code

Category

Cause

Error details

Measure

C280 ServiceCall

Scanner home 

position error 

The home position sensor does not 

become active in the designated period 

of time – The carriage does not reach 

the home position in the designated 

period of time. The sensor malfunctions. 

Power cycle the unit.

If the power cycle does not 

work to recover from the 

error, the unit needs repair.

The possible cause is 

the damage of the home 

position sensor, the belt 

that moves CIS, or the FB 

motor. 

C291 ServiceCall

Scan position 

detect error 

Scan position detect error – The black 

edge is not detected in scanning. 

Power cycle the unit and 

retry to scan. 

If the error occurs again 

in the next scan, the unit 

needs repair. 

The calibration sheet may 

not be installed properly.

none

Error

ADF cover 

open

ADF cover open 

Close the ADF cover. 

none

Warning/

Error

Scanner 

carriage 

warning 

Carriage warning – The carriage does 

not return to the home position after the 

scan. This error may occur when a user 

presses the document hard against the 

FB to scan. 

Perform the recovery 

procedure according to the 

guidance. 

F110

ServiceCall

Communication 

error between 

system CPU 

and Scanner 

CPU  

System CPU - Scanner CPU 

communication error 

If the error occurs frequently, 

check for the proper 

connection between the CU 

PCB and the SU PCB.

F111

ServiceCall

Scanner 

response 

anomaly

Scanner response anomaly 

The SU PCB, the scanner 

or the scanner firmware 

may have some problems. 

F112

ServiceCall

Controller 

response 

anomaly

CU-PU communication error detected 

by the scanner 

If the error occurs frequently, 

check for the proper 

connection between the CU 

PCB and the SU PCB. 

F113

ServiceCall

Scanner CPU 

exception

Anomalous program on the scanner 

side 

The SU PCB, the scanner 

or the scanner firmware 

may have some problems.

F114

ServiceCall

Scanner CPU 

exception 

CPU exception on the scanner side 

The SU PCB, the scanner 

or the scanner firmware 

may have some problems.