Nikon 35-70mm F2.8D lens not auto focusing from 35mm-50mm?

Try cleaning the lens and camera contacts gently with a lint-free cloth

If the gears are stripped, it will require an experienced tech to repair.

That being said, there should be a small switch near the lens mount to switch between auto and manual focus mode's, be sure that that switch is pointing to A. When set to M, the little screw recesses into the mount so it doesn't try to engage, when set to A, it'll extend very slightly.

Also, Nikon has manufactured two types of AF lenses - with the motor in the body and with the motor in the lens, as with most newer lenses. Your camera should have a small screw on the lens mount that drives the focus motor between the lens and the camera, but I'm not 100% certain on that. Your camera can focus lenses with and without this type of coupling. BUT, if that screw/motor in the body is not functioning, you'll only be able to use lenses which contain the focus motor inside them, or manual focus lenses (you can manually focus AF lenses too).

Hi md4, be a AF-S DX .
SWM or circuit problems in lens.
You have to take it to Nikon service to solve

This is done in the menu system. Where you change to mode to Close focus. Read the Manual/ If you do not have one www.nikonusa.com

Glad to have been of service.

Sorry to hear about your nifty 50 lens problems. The auto focus motor might have given out and needs repair. You should be able to focus manually with the lens.

You may be shaking the camera slightly when you press the shutter. If your shutter speed is 1/50 or faster, it shouldn't be a problem, but in very low light it may be that on auto the camera is setting a long exposure. Try using manual or S and setting the shutter speed for a shorter exposure. You may need to correct the exposure in software to lighten it up.

Depending on the type of interchangeable lens you have mounted on the camera, there may be a switch on the lens barrel for choosing between auto-focus or manual focus. The N55 also will not auto-focus with the newer Nikon AFS lenses such as those used with the Nikon D40 digital slr. Finally, there was a service bulletin on the N55 back in 2005. Nikon discovered a problem with the auto-focus and fixed it for free, but there may have been a time limit. Here is a link to more info about that:

http://www.nikonusa.com/Service-And-Support/Service-Advisories/N55-Service-Advisory.page

Hope this helps : -)

What camera body? This lens doesn't have an internal focusing motor and thus will not autofocus on the D40/D40x/D60/D5000/D3000.

Yes, that's normal. At 50mm the widest available aperture is f/4.5, and that works at the small end to make f/32 possible.