Olympus OM-1 Repair Manual page 163

G-8
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2. Position of Connecting lever (CA8425)
a: Stop position of CA8425 should be in this range,
b: After shutter charging, position of CA8425 should be this range,
c: Before shutter charging, position of CA8425 should be this range,
d: X direction of optical axis.
e: Y direction (right & left) of CA8425 should be positioned around this
vertical scratched line.
3. Position of Mirror releasing
+ Set shutter speed at 1/4 and charge.
+ Make mirror-up a little by turning mirror-up knob. Push
down shutter release button with but at this time hold the
mirror frame with your forefinger of right hand not to make
shutter release.
+ Lifting up the mirror frame with forefinger, shutter should be
released when the mirror frame is positioned in this
range.