I have a friend who is helping me with this and he said that the problem doesn't seems to be in that switch. I'm trying to explain what he is experiencing:
When the camera has power the shutter opens but, when he tries to take a picture, the camera doesn't make the regular sequence of taking a picture.
The motor always keeps running.
Every time he inserts the package, the counter restarts to 0 and keeps counting until 10.
If he tries to eject the picture by hand, the camera acts regularly but the shutter stays open. The internal mirror never seems to move.
Thank you, again Update:
We figured it out! The problem comes from the switch you were saying, I think. The S5 switch has a short circuit. Let's see if we can solve that