I got my D50 right after the family pack came out, so its around a year old. There was a freek rain storm that washed through the neighborhood I was in. The camera was in the car, so I grabbed it. On a whim, I had tryed some MF to try to catch the drops. When I put the camera back into AF, the focal ring locked, like the motor had engaged, but the AF assist light would not come on, and the focal ring would not travel.
Its doing this on my 28-55mm and the 55-300mm. symptoms are the same with the assist on and off
THe switch is just on the body. The lenses where the cheep ones (cheep being relitive I have learned with cameras). The fact that the lens will not travel what so ever is what concerns me. It takes pics fine on MF, but will not travel on AF
Sorry zipper you said the lens have no A/F are they Sigma or Tamron?
I have been playing with my D50 and I couldn't think of a setting other than the AF switch that has already been mentioned. Call Nikon hopefully your still under warrrenty and will not only get a fixed camera but a full check up and cleaning at the end to give you the feeling of a new D50 again.
Please let us know what happens all to often we never hear what it was we learn to with the final verdict. Jim