Weird problem with Rebel turing off and on

Colbitz wrote:

First I have seen that it was a defect of some cameras to happen all the time. My problem is intermittent and the camera was fine for years.

Anyway:

Canon 3ti

The camera will not turn on when some SD cards are within it. It will not turn on sometimes with all cards, but by removing the battery, removing the card, and putting both in some cards more than 80% of the time will have the camera turn back on and read the card. Removing all cards, removing and replacing the battery has the camera turn on again.

But then opening the card lid causes the camera to stop working. Some cards after doing the double replace will then work in the camera but some cards perhaps the high sizes (400 gig) which worked before will not allow the camera to turn on. The power light blinks for a few moments and the the camera is dead.

I suspected dampness or temperate change both which seem to correspond with this problem appearing. Sometimes after several weeks the camera works normally but then the problem reappears as is the case now - usually after a humid day or a cold one. Any experiences on a more permanent fix for this problem other than card swapping and waiting till it goes away again?

I had a similar problem years ago with a 50D. It ended up being a battery that was the problem. I tried troubleshooting through process of elimination I marked my batteries and memory cards, sure enough it was always one battery that caused it. Tossed that battery and issue went away.