Repair manual

over the front side of the shutter blade ear. - - It must be
safely rearward.
M - Check to see that drive blade has ample tension to open
contacts and that it does not wedge behind the shutter blade
in a manner to place excessive friction on the shutter blade.
The shutter blade should slide to the end of it’s travel
without hesitation when the winding knob is turned slowly back
and forth.
N - Any irregular motion or unusual sounds accompanying the slow
turning of the winding knob should be investigatd and
correted. Remember that this is the final testing operation
on the camera.
O - Note that the winding knob locks at “1”. By setting the knob
at a position equivalent to “0”, you can trip the shutter some
40 times before coming back to the locked position.
P - The indicator lamp burns when the shutter switch is closed and
should always turn off when the release button moves outward.
If it does not, bend the heavy switch blade to give about 1/64
opening between the contacts. If the movement plate ear is
bent rearward enough to cause contacts to partially close when
“Release Button” is fully out, straighten movement plate ear.
Then recheck switch action on oscilloscope.
Q - Analysis of oscilloscope picture in terms of shutter blade
action.
faulty operation of the shutter blades is also shown by the
oscilloscope picture. Operation of the front blade, which
uncovers the lenses, is shown by the trace from “A” to “D”:
D E
A F
Normally “A” “D” is nearly vertical, starting with a small
radius at “A” and ending with a small radius at “D”. If the
front blade is uniformly slow, the picture will be:
D E
A F
If the blade starts slowly, then accelerates to normal speed:
D E
A F