I have a Nikon Coolpix L830. I recently tried taking a close up picture (close up mode) and the image would not focus at all. Usually the close up mode is really sharp and clear. Can anyone help me?
Nikon lists the specifications for the Coolpix L830 here. In the focus range section under Autofocus they give the following information:
[W]: Approx. 1 ft. 8 in. (50 cm.) to infinity
[T]: Approx. 5 ft. (1.5 m.) to infinity
Macro mode: Approx. 0.4 in. (1 cm.) (when zoom is set to middle position) to infinity
To get the very close minimum focus distance you need to be sure you have put the camera in Macro mode and that you have set the zoom to the middle position.
If you're doing both of those things and the camera is not focusing properly it may be that the subject you are attempting to bring into focus does not offer enough contrast to the camera's focus system or the light where you are is too dim. Try focusing on an object with strong light/dark lines in bright light at a similar distance to see if the AF works.
If that doesn't work then the camera probably needs to be repaired. If it is still under warranty follow the instructions that came with the camera to obtain service. If the warranty is expired it might be more cost effective to just replace the camera with another one.