EOS 550D screen goes black and won't let me take pictures

[lovel]

the screen is flashing and goes black, I can’t take any pictures It says EXP. Sim and nothing else and sometimes shows the screen but then periodically goes black, I have a video but I can’t show it because of the subreddit, but I can send it to whoever thinks they can help or has experience with this camera I’ve looked online everywhere and can barely find information on it so anything would be much appreciated

[Waddizzle]

Make sure the camera is not in video mode.  A bad memory card can cause wild and weird things to happen to the camera, too, but not like you are describing.