http://www.nikonchat.com/slr-nikon-d3000/

My Nikon SLR D3000 refuses to take long exposure shots in the dark. Is there some setting I'm missing?
I was trying to take a picture of an exhibition of 10 seconds to get clues to the light, but there's no shutter button click. This changes as they try to take the same Throw in a brightly lit room.
Is likely to have on auto focus. If you can not focus so you can not take a picture. Switch to manual focus manual.