OKI C831n

Jam occurs in the middle of paper running path.

Motor operation check

Check item	Check work	Actions to be taken at NG
Paper feed motor driver, belt motor driver and ID motor	Confirm that the paper feed motor, belt motor and ID motor work normally by using the Motor & Clutch Test of the self-diagnostic mode. Check if any load exists or not.	Replace the CU/PU board, or replace the defective motor among paper feed motor, belt motor and ID motor, or replace the ID unit or belt unit. If any attempt of using new ID unit or new belt unit as a trial is going to be made, be sure to use the System Maintenance Menu FUSE KEEP MODE.
Paper feed motor, belt motor	Remove the MOTERCL connector (1) of the CU/PU board and check the following at the connector side. Several MΩ between pin-1 – FG Several MΩ between pin-2 – FG Several MΩ between pin-3 – FG Several MΩ between pin-4 – FG Several MΩ between pin-5 – FG Several MΩ between pin-6 – FG Several MΩ between pin-7 – FG Several MΩ between pin-8 – FG	Replace the CU/PU board.

Jam occurs immediately after paper has reached the fuser.

Motor operation check

Check item	Check work	Actions to be taken at NG
Fuser motor	Confirm that the fuser motor works normally by using the Motor & Clutch Test of the selfdiagnostic mode. Check if any load exists or not.	Replace the CU/PU board. Replace the fuser motor. Replace the fuser unit. If any attempt of using new fuser unit as a trial is going to be made, be sure to use the System Maintenance Menu FUSE KEEP MODE.

Temperature control while fuser belt running

Check item	Check work	Actions to be taken at NG
Detected temperatures of the fuser belt and the backup roller	Check temperatures detected at the fuser belt and the backup roller in the selfdiagnostic mode. Has abnormally low (lower than the room temperature) or high (250°C) temperature been detected?	Replace the fuser unit, relay board (P6Z PCB) or CU/PU board. If any attempt of using new fuser unit as a trial is going to be made, be sure to use the system maintenance menu FUSE KEEP MODE.

Check the installation condition of fuser unit

Check item	Check work	Actions to be taken at NG
Fuser unit	Check that the fuser unit is installed normally. (Is it pushed in down to the bottom-most point?)	Install the fuser unit correctly in a printer.