Q: iPhone 4S (iOS 9.3). Camera not working

I am having strange issue with camera of my iPhone (4s). Camera doesn't work on photo. It shows black screen first. When I get swipe to video it start working and able to capture video. But when I swipe to photo again it shows the view but unable to take photo.

Simple is camera is working fine in video case but not in photo.

I tried to restore setting, restore iOS and update iOS.  unfortunately no way is working for me.

Please can you help me to figure out the issue either it is hardware or software.

Thanks