    
Tronds_63
Tinkerer
Username: Tronds_63
Post Number: 19
Registered: 12-2011
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, April 04, 2013 - 02:08 am: | 
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My Nikon FA has a problem with the stop-down/aperture control lever. It moves so slow that in auto modes, it doesn't stop down the lens fully before the second metering is taken and the shutter speed is adjusted automatically.
When using f1.4 to f5.6 it works as is it should, but at f11 and f16 it selects a time that fits with f5.6 or larger but the lens is stopped down to f11 or f16.
This happens with several lenses, both AI-S and AF-D lenses. That rules out the lens as a problem.
Setting the camera ti bulb mode, I can watch the aperture control lever move. It starts out quite fast and slows down. It may use about 1/4 second to move from top to bottom. Sometimes it is so slow that the mirror sticks in the up position and the shutter is not trigged.
Holding the shutter release down in bulb mode, I can move the lever and it seems to have some flywheel connected to it. some mechanics with gears are spinning inside the camera when I move it. This slows down the movement.
According to the repair manual, the stop-down action should be finished in 40 milliseconds when stopping down to the smallest aperture. It takes way longer time on my camera.
This is a mechanical problem, but I need some more input about what to look for when I open it. |
