Nikon and Canon only repair shop. Web address: http://www.horizon-electronics.com
Took an EOS 28-105 lens with a sticky zoom in to be fixed. I talked directly to the technician who told me that this was a common problem with this lens. Fixed by appling more grease to internal zoom mechanism Also brought in my EOS 630 camera that has seen more than its share of sand. They checked the shutter and meter out while I waited. Everything was fine. I left the lens and camera (for cleaning). A few days later I returned and picked it up. They only charged for the lens.