Lens has sat for months - was using other lens for classes and recreational purposes. Put it on camera recently but it will not function. Seems to be jammed inside - will not advance or budge. Has not been rougly handled, but has been sitting an apartment that is not insolated next to the beach, where the climate is cooler and often foggy. Don't know if climate would factor in. Lens has has only been used a few times, and it worked fine during those uses. Can lens be fixed/repaired? Need recommendations. Photography is a hobby, and funds are limited. Am located in San Francisco - would welcome recommendations for reliable businesses that might look at it, repair at reasonable cost. Thank you.