https://community.usa.canon.com/t5/EOS-DSLR-Mirrorless-Cameras/T3i-battery-door-sensor/m-p/141125#M68482 <P>You might try a little denatured alcohol and clean it.</P> Mon, 18 May 2015 13:17:52 GMT ebiggs1 2015-05-18T13:17:52Z https://community.usa.canon.com/t5/EOS-DSLR-Mirrorless-Cameras/T3i-battery-door-sensor/m-p/141109#M68481 <P>So after google searches and testing, I've determined that my battery door doesn't always engage the door switch/sensor.&nbsp; With out the sensor triggered, the camera wont turn on.&nbsp; The door isn't damaged, never dropped, original door to the camera and orginal battery.&nbsp; Has anyone come up with a fix&nbsp; to make sure the door pushes the switch?&nbsp; I bought camera just under 2 years ago.&nbsp;</P> Mon, 18 May 2015 01:07:27 GMT https://community.usa.canon.com/t5/EOS-DSLR-Mirrorless-Cameras/T3i-battery-door-sensor/m-p/141109#M68481 braund3 2015-05-18T01:07:27Z https://community.usa.canon.com/t5/EOS-DSLR-Mirrorless-Cameras/T3i-battery-door-sensor/m-p/141125#M68482 <P>You might try a little denatured alcohol and clean it.</P> Mon, 18 May 2015 13:17:52 GMT https://community.usa.canon.com/t5/EOS-DSLR-Mirrorless-Cameras/T3i-battery-door-sensor/m-p/141125#M68482 ebiggs1 2015-05-18T13:17:52Z