Nikon D5100 AF only works in Live View

So I've had my D5100 close to a year, and it suddenly stopped auto focusing when shooting through the viewfinder. However, if I switch to live view the AF works just fine, so obviously everything is setup for AF. This incident occurs in every shooting mode, with every lens I have (standard 18-55 & 70-300, also 18-200). I'd appreciate any input or knowledge about this problem. Thanks!

Welcome..Have you moved something in the menu...Have you tried putting it back to the default settings...

The "live view" and the viewfinder use very different systems when auto-focusing. When you're using Live View your mirror is up so your camera is using a method called "Contrast Detect" to obtain its focus. When you're using your viewfinder your mirror is down and your camera is using "Phase Detection" method to obtain focus. So you cannot assume your phase detection AF is working when you're in Live View, it's entirely possible you have a problem that needs repair.

Thanks a bunch guys! Did the reset and it works fine now, and thank you Dave for informing/correcting about the different mirror angles and detection modes.

Yep, as always, lots of great answers/help here at Nikonites!! Thanks all....

Pat in NH

I wouldn't hurt to check the settings on the camera anyhow would it?