Hello - I've had a Canon 6D for over a year and love it, but today ran into a major issue where the camera would not turn on at all. I tried two separate and fully charged Canon batteries, as well as changing the lens, removing the SD card and replacing with a different card, but had no success with getting it to turn on. Any suggestions? I've tried looking elsewhere online and have not seen anything on this topic.
Have you been using the camera regularly, say within the past month? I ask because batteries are in a constant state of drain and if your haven't used the batteries recently, they may have lost their charge. (Sorry if this sounds silly to ask but from what you wrote it could be that you took two batteries out of your camera bag, having left them fully charged months ago) and they don't work.)
You'll probably need to reset your camera. Refer to your instruction manual or the next post or two will make a better explanation.
Have you tried connecting it by USB cable to your computer and see if you can communicate with it using the EOS software?
Did you shake, drop, knock, or otherwise bash your camera anytime recently?
Have you measured the voltage of the batteries at the terminal to confirm that they have a charge?
If the camera thinks the battery door or memory card door are not fully closed, it will not switch on. Check to make sure the tabs on the doors (that press the little micro-swtich to indicate the door is closed) aren't damaged and that both doors completely close.