Hans Fisher , Sep 08, 2008; 01:49 p.m.
Hello, I have the Canon 75-300 USM III lens. When I shoot at aperture around 8.0 I get an error message on XSI-err
01-faulty connection between lens and camera. I have tried cleaning the lens contacts. At aperture 4 or 5.6 it
seems to not do it at all as well as f13 and bigger. The lens makes a noise- a short quiet bzzzzd noise-like it is the
aperture stuck or something? Could this cause any damage to the camera? The lens also makes some clicking
noises when zooming. Is the lens just shot or is it a cleaning issue maybe? I know this is a lower end lens but is
this a common problem? Any ideas on fixing it at a low cost? Any ideas on a good replacement?
Jason Hall 
, Sep 08, 2008; 02:14 p.m.
Sounds like to me the Aperture diaphram is sticking at that point (f8-f11). f4 and f5.6 are your largest apatures when zoom to 75mm and 300mm respectively. So the Apature is not moveing at all at those settings unless you are stopping down to f5.6 while zoomed to 75mm.
Anyway, how did you clean the connections? Many say to use a pencil eraser. Just be carefull to not get shaveings into the camera.
It should not cause damage to the camera as the issue is most likely mechanical....but I really don't know. The clicking sounds you hear make me think mechanical as well. I would not think it is worth fixing. I beleive it sales for $175.00 new USD.
Jason
Rob Bernhard 
, Sep 08, 2008; 02:17 p.m.
If your lens is broken (which it may be) you can contact Canon to see what the repair cost would be. You may find that buying a new one would only cost a little bit more.
Rob Bernhard , Sep 08, 2008; 02:18 p.m.
Er, sorry, forgot to add: if your lens is out of warranty. If the lens is still within the warranty period, then the repair by Canon should be free.
