Screen only shows: The mode dial is not in the correct position.

My problem is that when I turn on the camera that says: The mode dial is not in the correct position. This shows on the screen, all in black background preceded with an exclamation mark! in red. And the truth is that I do not know what the problem is, some people suggested me to opening it and cleaning the contacts, but I doubt that it works, since I repeat only that text appears on the screen and after 10 seconds it turns itself off. I changed the battery, the memory card, I touched all the buttons but nothing has changed. I hope you can give me a clue to solve it. Thank you.