Nikon auto focus lens not working, only in manual

Yes and no. I assume the lens is of more or less the same vintage as the N75? If so, the lens will fit onto the D5000. All of the camera's exposure and metering modes will work properly. However the lens lacks an interal focus motor and thus will not autofocus on the D5000. You can focus manually, and the green focus indicator in the viewfinder will continue to work.

The F/stop isn't supposed to change when you focus. Depending on the camera, you change the f/stop by either turning the aperture ring on the lens or turning a command dial on the camera body.

Great, glad to hear you're all set now.

Is the lens aperture ring set to the "a" position?

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 : -)

I will try to help you, but please understand that my experience is with Nikon film cameras. Assuming that the D60 works in a manner similar to a Nikon 35 mm body and that Sigma macro lens work like Nikon macro lens, you should be able to determine the usable subject to lens distance by experimentation. First, make sure the lens is in the macro mode. To do this you must set the auto-focus mode control to the manual focus mode (see your manual). On Nikon lenses, you must first set the focus ring to infinity, then move slider switch, which has two positions marked; "normal" and "macro., to the macro position. You should now be able to rotate the focus ring to the macro range. Use the zoom ring to zoom in and out and focus with the focus ring. The the range over which the lens to subject to lens distance will yield an in focus image will be rather limited and in the range of an inch or so to 6 or 8 inches.

We tried the same lens on another Nikon (D90) and auto focus did not work.
We mounted a new set of lens on the original D40x, and it worked.
Turns out the 2 year Nikon lens (18mm-135mm) was bad. Nikon lens have a 5 year warrantee. The lens will be sent back to Nikon with no service or shipping charge.

Thanks,
K

I assume the lens had the impact. The 18-55 lens has the built-in motors for auto-focus.
Try switching to manual focus (on the lens). If this works, the lens may not auto-focus anymore.
Try it and let me know.
cheers,

The Lens focusing motor is broken and it is replaceable

I had the same problem. My issue was with all my lenses. I solved it by going to the menu and selecting the custom setting menu (pencil icon). Then from the right menu select the AE-L/AF-L and press OK. Then make sure it is set on AE/AF Lock. Presto...all my lenses worked on auto-focus.