How does an LCD display work?

Canon Rebel will not take a picture. The flash and focus are work, but no display on LCD and no shot....?

• I have a Canon rebel XS that has suddenly stopping taking pictures. The flash will pop up and flash, the auto focus works, but when I look into the view finder it just says, "Busy". The display screen on the back does not show anything at all no matter what buttons are pushed. The dial for the power and all the different modes is working, and the shutter button is obviously working as well, since the flash and auto focus are functioning... I would normally just assume that the display screen had gone out, but that doesn't seem to be the case, considering the shutter won't close and it won't snap a picture. The camera has some wear and tear on it, but was functioning with no problem just a few days ago, and nothing has happened to it since then. I don't have much money to spend taking it to someone, and am secretly hoping there is just some dummy thing I am doing wrong that may fix it. Please give me your advice as to what to do... and PLEASE, if you know nothing about eos cameras, do not comment on this just to get points. I am a real person with a real issue! Thanks!

• Answer:

  If there is not enough light in your surrounding atmosphere, the camera will not know how to make an exposure and the symptoms will occur as you mentioned. You can easily test this by pointing your camera a lighted source like a light or the sun. Otherwise you need to take it to your nearesr canon service centre to get it serviced. There is nothing much we can really do to solve your problem without actually seeing the camera in my hands; despite being a 'real' person.