Hi i own a 7d the problem is very likeiy to be in the little pin under the spring on the hot shoe on the right hand side i have used isopropyl alcohol and a tooth brush when it has worked i then use a little crc or wd 40 on the end of a tooth pick to keep the pin from getting stuck again i hope this helps Update (03/08/2019): Hi again if you are living in new zealand i can give you an address to send your cameras to for repairs its CW Services ltd 62 church street timaru 7910 new zealand —-or www.camerarepairs.co.nz Greg is one of the best techs in nz for canon repairs I have used him a few times and his costs are very fair