There doesn't seem to be a "right" place to post a "broken item" question, so I'll post here. I have a Sigma 105mm macro which was purchased new about 10 years ago. It has been working fine until 2 weeks ago. I changed lenses for one shot and put the 105 back on the camera and when I turned the camera on the lens was making a sort of hesitant grinding sound when it would focus, but other than that it was focusing alright. Today I was using the 105 again and there was not a lot on the trail my husband and I were walking so I'd only turn the camera on when I found something to shoot -everything was fine till the last shot. I turned the camera on took a few frames and when I turned the camera off, the lens made this awful grinding sound but didn't move. I took the lens off and checked it out, put it back on and when I turned the camera on it made the same grinding noise. I turned the camera off and the lens continued to grind for a few seconds before it stopped. When I got home I cleaned the lens contacts and tried the lens again....still grinding. My other lenses all work fine. So what do you all think, should I make funeral arrangements for this lens, or do you think it might be something easily repaired?