Aperture stuck at f22 any ideas why

[CaptainPenguin]

Yesterday for no apparent reason the aperture on my Sigma 17-35 f2.8/4 stuck at f22 and will not shift,before I take it for a repair quote anybody got any ideas what has caused it

[pearce_jj]

sounds like the blades are simply physically jammed?

[dapprman]

Silly question as I don't know that specific lens but have a number of Sigmas myself.

Does it have an aperture ring ? and if so does it have a locking tab that you may have knocked in to place ? (as I did the reverse to on my old 70-300 APO D HSM 3.5-5.6)

[CaptainPenguin]

Silly question as I don't know that specific lens but have a number of Sigmas myself.

Does it have an aperture ring ? and if so does it have a locking tab that you may have knocked in to place ? (as I did the reverse to on my old 70-300 APO D HSM 3.5-5.6)

Sorry should have said its an EOS fit so no aperture ring,it was actually playing up for a few weeks sticking and then clearing but now locked solid at f22

[sheddy]

Mine did the same so I bought another which I toe punted across a room ..... you know when you drop something and then stick yur foot out to stop it impacting on the floor? That would be the mis-timed intention.

Both17-35 are currently sitting on the shelf. With the sticky one, I found that by operating the shutter in continuous mode and zooming in and out at the same time it would come unstuck.

[Shadow]

Definitely sounds like stuck aperture blades.