Upside Down Nikon F2 Shutter

[comet_catcher]

I've got a Nikon F2 with a unique shutter problem. After fully winding the shutter advance, upon release the mirror comes up about 80% of the way and just hangs there. There is a subtle click but the shutter does NOT release. It is not attached to the foam bumper so that is not the issue. If I manually push the mirror up even slightly, it will complete its travel and the shutter releases. Now for the weird part. If I hold the camera upside down the mirror and shutter both work flawlessly--at all speeds. Even sideways in portrait position it works just great. But as soon as I flip the body right side up the mirror hangs and everything just freezes. Again, I can complete the cycle by pushing up slightly on the mirror, or by pushing down slightly on the mirror return arm. It will also complete a cycle if I nudge the release lever under the bottom plate. I can freely move the mirror prior to winding the shutter so it is not physically stuck. The gearing, springs and release arms under the bottom plate appear to move freely and are not jammed in any way. Any ideas why the body orientation should so drastically affect the shutter? Thanks.

P.S.- I just tried the mirror lock up and discovered that the shutter works fine with the mirror locked up -- in all orientations. So it is definitely related to the mirror somehow. I just can't understand what gravity has to do with it, especially when it seems to works when fighting gravity but not when moving with it.

 

[santino]

Well something seems to be gummed up that prevents the mirror from completing it‘s cycle and so it prevents the shutter from firing. Obviously the mirror has to be raised before the shutter fires. Gravity seems to help the mirror to complete it‘s cycle. To me it sounds logical, doesn‘t it?
It is probably time for a proper CLA.

 

[Timmyjoe]

Needs a proper CLA. That should straighten it out. As @santino mentioned, the mirror is slightly gummed, which is keeping it from rising all the way up.

Best,
-Tim

 

[comet_catcher]

I decided to open up my camera to see what was going on inside. I have extensive experience with the F3 so I thought this shouldn't be too hard. I was correct.

After removing both top covers, I proceeded to remove the front plate. I usually leave in the mirror box and remove that separately. I find it much easier to replace it if done by itself. Much easier to align all the pins and levers. Makes getting the front plate back on and getting the self timer correctly aligned easier as well. Looking from the front, all the mirror linkages that raise the mirror are on the left side. It was pretty junked up with years of hardened grease and dirt, so I used some 99% isopropyl alcohol to degrease everything. Once it was cleaned up I could see the problem. The depth of field preview lever that protrudes out into the mirror box to engage with the lens had been severely bent inwards (towards the mirror) so it was rubbing on the outside of the mirror box housing. The springs could move it a bit but as it got further along the friction became too much and the mirror just got stuck. When the camera was upside down it got a gravity assist and could complete the cycle (you can see the rub marks in photo #2). I applied a little pressure and gently bent the arm back into position.

I have decided to replace all the foam and dampening material while the camera is apart (there is an extensive amount of it around the mirror box). It not just cushions the mirror but also dampens the mirror rebound. That is the cause of the familiar "twang" when the shutter is released mentioned by so many people. I have to admit as this was my first venture into an F2, I was a bit hesitant. But now that I have seen the insides I find it much easier than the F3 with all its electronics. Cheers!

 

[splitimageview]

well done!

 

[seany65]

Should've just hit it with a hammer. 👍