Trying to clean the controller didn’t work for me either. It also made the situation worse by damaging the delicate flex cable and making the “set” button non functioning. I also broke one of the small pins at the back of the 4 way button so I had to look for a whole new unit. Fortunately, I could find one from aliexpress. I replaced the part and now everything is ok. The feel on the set button is not very good though. But it is way better than a non functioning button. I bought the whole unit for 26 dollars but if you haven’t damaged your plastic button part you can find the flex cable alone for much cheaper. Here is my order: https://www.aliexpress.com/item/For-Canon-6D-SET-key-to-confirm-6D-key-back-button-on-the-back-wheel-with/32859645101.html?spm=a2g0s.9042311.... I really appreciate this topic and I thank the author and every contributer who saved me from paying hundred dollars to Canon service here in my country. Great job dudes!

Hi dude. I did all the steps and disassembled the camera and I removed the IR filter from the sensor. All is good until that point. And then I assembled the camera in reverse order but now there is no display on screen. In my first attempt I got the menu working but I got no live view display or photo. Then I re-opened and assembled again. This time there is just nothing. Camera turns on but no display, no messages. the zoom button, on/off and even the video record button works all well but no display.. Any thoughts on this pls?

PS: This is an excellent tutorial by the way. I must have done smth. wrong, otherwise I had no issues on disassembly.