My nikon d5100 shutter is "locked" and i am not able to push button down until on manual. what happen?
1. Are you using AF-S lenses
a. If yes, do you have enough light for Autofocus/Auto Functions to work
b. If not, you have to work in Manual Mode.
2. Try another AF-S lens, see if that works.
a. If not, it could be the camera or take the lens cap off LOL