Canon Staple Finisher-AA1 Service Manual page 171

5. Adjustment
<Procedure of adjustment>
1. Open the front cover [1], and then pull out the saddle stitcher unit [2] until it stops.
[1]
[2]
2. Push the plate spring (left/right) [2] and then pull the saddle stitcher unit [1] to the service position.
[2]
[1]
[2]
3. Remove the 2 screws, and then remove the lower right saddle cover.
2x
4. Loosen the 3 screws.
3x
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