I understand your desperation. It caused me to go back and double-check my previous statements, based on a discovery long ago. My camera is an early SL1. It does have a small (4x7 mm) rectangular switch centered between the rubber part of the eyecup and the hot shoe. I did not find it documented anywhere and have no idea of its function(s). It might relate to a 90 degree viewer attachment which I know nothing of. I know you have a different camera. In desperation, maybe yours somewhere has a switch related to whatever the function on mine is.