David, first off, I'm assuming the 85 is very similar to other Pentax FA lenses. Second, I'm assuming the problem is the same as I've had with other FA lenses. That said I have solved my problem by gently inserting a sharp x-acto knife blade to compress the two spring leaves that hold the aperture in, and out of, the A position. The example photos are of an FA28-70/4 (My favorite!). The first shows the position of the spring leaves. The second where the x-acto needs to go. The third is where I think you're hung up since you say you're _past_ the A position.
http://www.donsauction.com/pdml/farepair.htm Working the blade back and forth while gently wiggling the aperture ring should free it if this is the problem. A lot of ifs but I hope it helps. Don (Now let's see if I can get THIS one back together!) :-) > -----Original Message----- > From: David Mann [mailto:[EMAIL PROTECTED] > Sent: Sunday, January 01, 2006 12:57 AM > To: [email protected] > Subject: Reassembling A*85/1.4 > > > I have a problem... > > I've been taking apart a number of lenses today to clean them - a > couple had small spots of fungus and a few others were a bit dusty > inside so I decided to clean those up as well. Most just got a good > rear element cleaning as I don't often pay much attention to that end. > > The A*85mm f/1.4 has a fixed rear element and it was quite dusty in > there, but to unscrew the rear-element assembly you need to remove > the aperture lever first. To get at the aperture lever assembly you > have to remove the whole rear assembly that holds the aperture ring > and the mount. > > I managed to get it apart without too much trouble but now I'm having > trouble putting it back together. When I was removing the rear > assembly which holds the aperture ring and the mount, the aperture > ring slipped around a bit further than it normally goes and it came > slightly outwards, and now it's jammed up. I suspect some springy > internal piece has stuck itself in a groove and I just can't work out > how to get it free. The aperture ring is quite loose but it won't > rotate more than a few degrees and it can't be moved in or out by > more than a couple of millimetres. > > Can anyone offer advice or am I going to have to sheepishly trek into > the camera shop with a bag of lens parts? > > Because the part that holds the aperture lever has slots instead of > holes for its mounting screws, I suspect that I've also thrown out > the accuracy of the auto-aperture. I'm not sure how I can calibrate > this so I might just fit it in the centre and test it after the lens > is reassembled. I rarely use lenses on "A" so it's not too big a > problem. > > BTW for the fungussy lenses I had varying results with isopropyl > alcohol so I switched to CRC Glass Cleaner which I suspect is > basically the same stuff as Windex. I use this product for cleaning > glass prior to picture framing and it's excellent. Squirt some into > a tissue and rub it on, then rub it off with a dry tissue. Use a > blower to remove the tissue dust and you have perfectly clean glass > with no residue. > > Also I am really thankful that I didn't need to take apart my 200, > 300 and 400mm lenses. Those ones are mechanically quite complicated. > > - Dave > >
