aperture repair on "sigma fisheye ys 16mm f2.8"

[aran]

hi there mflenses forum!
i need a little help repairing this old lens and hope you can help me. it's the sigma fisheye ys 16mm f2.8 filtermatic - the problem: the aperture won't work. note: i'm not an expert in repairing lenses, but i thought it is worth a try since i rescued it out of the trash.

the aperture itself works perfectly fine, but the metal pin which connects to the aperture ring (the ring to change the aperture when the lens is assembled) does nothing - feels like it's hanging around loose with no connection to the aperture itself.

a picture of the lens, disassembled as far as i could get:


the lens with removed bayonet:


so my question here is: should the blue marked pin transmit to the outer aperture ring? and how can i fix this problem, including the question how to disassemble the lens further - because i can't remove the filter system out of the lens and therefore can't reach the aperture blades.

note: i also googled about the lens, but this seems a very uncommon type with rare information about it. what i found:

http://forum.mflenses.com/how-to-repair-aperture-of-sigma-18-2-8-m42-t31100,highlight,%2Bsigma.html
and
http://www.kyphoto.com/classics/forum/messages/6899/7813.html

since these are quite different build these things weren't useful to me.

any help or hint would be very appreciated! if photos of other angles are helpful, please tell me - i will upload them.

regards,

aran

[aran]

i dont know why the post above is that messed up, bbtags are alright.

edit: if i remove this post, my first won't work properly. if it stays, everything works out fine. so, sorry for double posting.

[WolverineX]

first post of a new member never shows photos, anti-spam measure of the forum

does that spring on the first pic move at all when you move pin marked with blue? if it does but aperture won't close, then that spring has lost it's tension and should be replaced. if it doesn't then something inside that glass element has uncoupled and you should open that glass element. as i see no visible screw or notch on the glass element to open it, you probably have to remove it and try to open it by twisting forward and rear metal part of the element to unscrew them , but carefully not to lose any part of it. and then see if there is anything loose inside of the glass element and try to fix it