OKI C531dn

Jam occurs immediately after the power is turned on. (1st tray)

Check condition of the paper running path

Check item	Check work	Actions to be taken at NG
Paper running path of the front unit	Open the front cover check if paper is not jammed in the paper running path.	Remove the jammed paper.

Check condition of the mechanical parts

Check item	Check work	Actions to be taken at NG
Hopping sensor and IN sensor lever check	Check the sensor lever shapes and operations for any problem.	Replace the sensor lever(s) with proper one(s).

Check condition of electrical parts

Check item	Check work	Actions to be taken at NG
Check the detection condition of the sensor signal.	Confirm that the sensor signals are normally detected by using the Maintenance Menu SWITCH SCAN function.	Replace the CU/PU board, or appropriate sensor(s) or connection cord(s)
Hopping sensor and IN sensor output level check	Check the following signals by using the CU/ PU board HPSNS and RGSNS connector 16: HPSNS pin 2: Hopping sensor RGSNS pin 5: IN sensor Check that the above signal levels are changed by operating the levers of the sensors.	Replace the CU/PU board.