I normally have a grip attached to my 50D. The other day I removed the grip to take my 50D into the photography class I'm teaching at the moment. Were were doing some in class still life photography.
I was demonstrating a few lighting techniques and showing the result on the LCD screen of my 50D. Anyway, after awhile the Main Dial was kind of "free wheeling" and not activating any of the settings unless I pressed down hard on the dial whilst turning it.. This wouldn't have been too much of a problem if the grip was attached.
The first thing I thought of was a bad connection in the contacts of the Main Dial. When I got home I gave the Main Dial few good bursts with a rocket blower, and blow me down, it worked. Bloody dust I'm thinking causing a bad connection in Main Dial.
I check the Main Dial a couple of times a day just to make sure. Everthing is cool
