D5100 will only take photos in live preview mode

Hi I'm new. I've got a D5100 that has never been dropped. It was working fine yesterday. Now all of a sudden it will only take photos if I use live preview mode. If I use the viewfinder it will click once but I don't hear the 2nd click and in preview mode the screen is black. If I switch to auto mode it seems fine but this is not a setting I use. Any suggestions. Have tried swapping batteries lenses etc

Check the dial on top of the camera and make sure it is in the right shooting mode. It may have been bumped into Q or MU if the D5100 has them.

Try resetting the camera settings. Usually it ends up being an error where some setting gets mistakenly changed. Hope this works for you.

Hi Guys. I only use A and P on my camera. Will try a reset tomorrow. Is it straightforward? Not done one in the 2 years I've had the camera. Really appreciate your feedback - this is a great forum. Left the camera at a friends tonight or I know I will sit up with it all night long..........

very easy explained in manual.

Do a full reset. If the problem persists, then :
Check if the mirror is stuck
. Switch off
. Take the lense off
. Check if you can see the mirror or the sensor. If it is sensor then the mirror is stuck.
. If you can see the mirror, then cycle a few times between live view on and live view off.

If you are still not able to take shots in View Finder mode, then get the camera checked for logic board fault.