"D7100 autofocus not working for a while, do i need to worry?"
Got my D7100 with the kit lens about a month ago. then bought the AF-S DX 35mm f/1.8G about 3 weeks ago and been using this lens ever since. Until yesterday, all of a sudden the lens is making some weird noise during auto focus (auto focus still work but making a louder noise then usual). I turn the camera off and turn it back on, then the auto focus not working at all. then i tried taking out the battery and reinstall it, removed the lens, remount it again and all didn't work. finally i mount the kit lens back and auto focus works again. then i process to remount my 35mm lens and its back to normal. Is that something i need to look into or not worry about? anyone got the same happened to them?
#4. "RE: D7100 autofocus not working for a while, do i need to worry?" In response to Reply # 0
Since the kit lens autofocuses without issue, it is probable that the noise comes from the 35mm lens as the G series lenses use electronic control for their autofocus. AF-S lenses do not use the mechanical screw drive for autofocus.
Personally, I would either have the lens exchanged or repaired under warranty. It will never heal itself and Murphys Law says that it will die at the worst possible time.
#5. "RE: D7100 autofocus not working for a while, do i need to worry?" In response to Reply # 0
It's possible that you hadn't mounted the lens securely on the body, and the electronic contacts weren't making good contact. I have done this myself on a few occasions resulting in exactly those symptoms.