Canon imageRUNNER ADVANCE 8105 Series Manual page 199

7) Remove 1 connector [1] and 2 screws [2], and then remove the duplex side registration sensor assembly
[3].
8) If no problem is found with the side registration sensor (PS31) [1], the side registration detection flag [2],
and the side registration slider [3] after checking how these parts are mounted, remove 1 connector [4], 1
wire saddle [5], and 2 screws [6], and then replace the side registration motor [7].
9) Reassemble the parts from step 7) in reverse order.
10) Make a 2-sided test copy, and see if a jam does not occur.
[Replacement Part]
FK2-2069 MOTOR, STEPPING, DC (M16)
WG8-5848 PHOTO-INTERRUPTER, GP1A173LCS0F (PS31)
FC8-7295 FLAG, SIDE REGISTRATION DETECT
FC9-5450 SLIDER, SIDE REGISTRATION
pg. 199