Oki MC770 series Maintenance Manual - page 174

45376001TH  Rev.1 

173 /

Oki  Data  CONFIDENTIAL

7. Troubleshooting and repair procedure

Check item

Check work

Action to be taken 

at NG

(3-2-4) Check the system connection

Paper feed motor 

drive cable

  Check the connection condition of the cable. 

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. Check 

also that cables are assembled without any 

abnormality.

  Replace the 

cable with the 

good cable 

that normalizes 

the connection 

condition.

Paper feed motor 

drive cable

Check that any cable is not pinched during 

assembling of the printer. 

Remove the HP_PSZCL connector 

 of the PU 

board and check the followings at the cable side. 

Short circuit between pin-1 – FG 

Short circuit between pin-2 – FG 

Short circuit between pin-3 – FG 

Short circuit between pin-4 – FG

  Replace the 

cable with the 

good cable 

that normalizes 

the connection 

condition.

Paper feed motor

Remove the HP_PSZCL connector 

 of the 

PU board and check that approx. 3.4

Ω can be 

measured between pin-1 -pin-2 at the cable end, 

and that approx. 5

Ω can be measured between 

pin-3 -pin-4 respectively.

Replace the 

paper feed motor.

(3-2-5) Solenoid operation check

Paper feed clutch

Confirm that the paper feed clutch or regist 

clutch works normally by using the Motor & 

Clutch Test of the self-diagnostic mode. 

Remove the metal plate from the right side of a 

printer so that the clutch becomes visible. Then, 

check operation of the clutch. 

Replace the PU 

board, or replace 

the paper feed 

clutch or regist 

clutch.

Check item

Check work

Action to be taken 

at NG

(3-2-6) Check the system connection

Paper feed clutch 

cable    

  Check the connection condition of the cable. 

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. Check 

also that cables are assembled without any 

abnormality.

  Replace  the 

cable with the 

good cable 

that normalizes 

the connection 

condition.

Paper feed clutch 

cable

Check that any cable is not pinched during 

assembling of the printer. 

Remove the CL1 connector   of the PU board 

and check the followings at the cable side. 

Short circuit between pin-1 – FG

Remove the CL1 connector 

 of the PU board 

and check that approx. 240

Ω can be measured 

between pin-1 and pin-2.

Replace the 

solenoid and re-

assemble the 

printer correctly.