Oki ES3640MFP Component Replacement Manual page 54

Upper Left Door Detect Sensor
1.
Remove the Eject Assembly.
2. Release the 2 hooks that secure the Top Output Tray Stack Full Sensor cover.
3.
Disconnect the Top Output Tray Stack Full Sensor.
4.
Release the wire that surrounds the sensor.
5. Release the 2 upper hooks of the Outer Exit Chute.
6.
Separate the outer and inner chutes enough to disconnect the Side Output Tray Stack Full Sensor.
7.
Release the 2 lower Outer Exit Chute tabs by gently prying the two chutes apart.
8.
Release the hooks that secure the sensor to the Inner Chute.
9. Disconnect the sensor connector to remove the sensor.
Eject assembly
Upper Left Door Detect Sensor