aperture not working anymore

I have the BM Cinema camera and a Canon 17-35 L series lens. I have been shooting with in and I am no longer able to change the aperture on this lens. If I try to change it, it jumps to f/32 and freezes up. The lens did get hit the other day while shooting, but nothing seemed to happen to it. I attached it to my Canon 60D and it worked perfectly fine, but on the BM camera nothing happens with the aperture. I have attached all my other lenses and they work normally. Has anybody had this ussue?