Yesterday I went to use my 450d for my sons christening and it won't work. Here are the faults
1: turns on but Ltd won't work 2: it focuses but won't take a picture just says busy 3: it makes all the right noises flash pops up and numbers display at bottom of view finder but that's all.
You could try resetting the camera. There should be a menu selection that does it.
You could also have a memory card failure. Try a new card. Make sure your current folder to save images is not full, and that the next available number for a saved images is actually available. Folders have limits on how images that can be saved in one folder.
-------------------------------------------------------- "Enjoying photography since 1972."
