OKI C931

Jam occurs immediately after paper feed is started. (Multipurpose tray)

Check condition of the paper running path

Check item	Check work	Actions to be taken at NG
Paper running path of the multipurpose tray	Check if paper is jammed or not in the paper running path.	Remove the jammed paper.
Sheet Receive of the multipurpose tray	Confirm that the Sheet Receive has moved up normally. Confirm that the support spindle and spring of the Sheet Receive have been installed in the specified positions normally.	Correct installation of the above parts so that the Sheet Receive moves up to the specified position normally.

Check condition of the mechanical parts

Check item	Check work	Actions to be taken at NG
Check the sensor levers of the paper entrance sensor 2	Check if shape and movement of the sensor levers have any abnormality or not.	Replace with a normal sensor lever.
Right side cover	Confirm that the locks in the right and left of the right side cover are locked normally.	Replace the Right side cover assembly
Check the feed roller, the pickup roller, and the retard roller.	Check if any foreign materials such as paper dust on the surface of the feed roller or of the pickup roller or not.	Remove the foreign material.
	Check if the feed roller has worn out or not.	Replace the feed roller.

Motor operation check

Check item	Check work	Actions to be taken at NG
Hopping motor	Confirm that the hopping motor works normally by using the Motor & Clutch Test of the self-diagnostic mode.	Replace the PU/CU PCB or hopping motor.
Hopping motor driver	Confirm that the hopping motor works normally by using the Motor & Clutch Test of the self-diagnostic mode.	Replace the PU/CU PCB.
MPT clutch	Remove the HOPM connector of the PU/CU PCB and check the following at the connector side. 1 MΩ or more between pin-1/-2/-3/-4 and FG.

Check the system connection

Check item	Check work	Actions to be taken at NG
Hopping motor drive cable	Check the connection condition of the cable. Visually 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. Also check that cables are assembled without any abnormality.	Normalize the connection condition. Replace with a normal cable.
Hopping motor drive cable	Check that any cable is not pinched during assembling of the printer. Remove the HOPM connector of the PU/CU PCB and check the following at the cable side. Short circuit between pin-1/-2/-3/-4 and FG	Replace the cable and normalize the assembled condition.
Hopping motor	Remove the HOPM connector of the PU/CU PCB and check that a resistance of 10Ω or less can be measured between pin-1 and pin- 2 and pin-3 and pin-4 respectively at the cable side.	Replace the hopping motor.