Canon PC800 Series Service Handbook page 48

CHAPTER 2 STANDARDS AND ADJUSTMENTS
8) Use the rotary switch (SW2) on the ADF controller PCB to adjust the original leading edge
stop position.
Moving the rotary switch by a single notch changes the original stop position by about 0.3 mm.
Press the push switch (PSW) after deciding on a position to discharge the copy paper and store
the optimum value.
Relationship between Rotary Switch Direction and Original Position
Direction of rotary switch
2-34
PSW
ON
1 2
SW2
Figure 2-59
Clockwise
Counterclockwise
Table 2-5
0
Position (shift) of original
Toward leading edge
Toward trailing edge