Fixing The Exposure Meter
in auto mode, the needle moved, shutter speed varied, but the aperture was stuck at f16.
|© refinder 04/09/2006|
|i looked around and noticed that the ev-lever did not move, which led to its coupling counterpart, the aperture lever on the exposure meter. couldn't really see anything without taking it off the body.|
|took these two screws out, and that's it. i also unsoldered the blue wire, so that the lens and exposure meter became completely separate from the body, for convenience.|
|the ev-lever connecting to the aperture ring in the lens was working. the aperture was opening and closing when it was pushed. however, its counterpart on the exposure meter, a coupling hole riding on a copper lever that pivots around the axis of the needle movement did not move at all. i pushed the copper lever hard, it did not move a bit!|
|the ev-lever is connected to the aperture ring in the lens, controlling the opening and closing of the aperture. the spring, when hooked up to the pin on the shutter release shaft, will cause the lever to push on the ev-lever-roller, so that the aperture will be in fully opened state all the time. it only stops down when the shutter release button is pessed.|
|judging from the way the ev lever works, the arched slot, and the spring loaded aperture stopping down lever pushing on it, this copper aperture lever should move. since i couldn't see it connecting to anything other than the needle movement axis, i decided to take the movement set screw out. to facilitate that, the black cover was taken out first.|
|once the movement was removed from its base plate, gooy sticky green
rust was everywhere on every interface, between the base plate and the
washer and the lever, the lever and the movement axis! don't really
understand why there was so much rust here, and barely any anywhere else.
but it froze the lever hard alright. separated all these parts and cleaned
each surface, then wiped them with a piece of cloth damped with oil.
the copper aperture lever, the hole, the spring loaded stopping down lever all worked smoothly after that.
|now that i know, when the exposure meter is decoupled and this copper lever (3) is still in the up position, that is a sure sign of gummed up moving parts in the meter. when decoupled, other springs should take effect, in the absence of the ev-lever spring, and push this copper lever down, as what will happen when the shutter release button is pressed.|
|the second problem in this area was that the glue on this black nylon strip had turned into very stick goo. this is where the end of the needle is pressed down to, to stop the needle when the shutter release button is pressed. the worset thing was this black sticky goo had gotten all over the end of the needle, the pressing plate, and the base plate. i could see how easy the needle could get stuck somewhere along the arch and became frozen.|
|the cleaning of these three parts was difficult. the needle was very delicate, i was afraid of knocking it off its bearing and had it totalled that way.|
|patience and care. every thing was clean at last, and the original
black nylon strip was replaced with a new piece of black cloth, with a
bit of superglue.
then the auto aperture worked.
|Hi-Matic 9 Repair|