Nikon N55 Won't take picture in Auto Focus Mode?

Try resetting the camera by pushing both rewind buttons (two buttons with red rewind symbol), and when the motor stops running open and close the back door then try again. If not it could be as simple as a bad release switch (the switches on the N55 and N75 were garbage) or a electronic problem. Also check to make sure you did not pop the shutter blades out of position when loading film. Remove the lens and gently lift up the mirror with a fingernail and make sure the blades are flat.

Could be your lens is not communication with the body. If the lens is not telling the camera that the AF has locked on an object then it won't allow the camera to fire. Make sure that the camera is indeed locking the AF on the object. If there isn't enough contrast (for example a plain wall) then it wont be able to lock onto it. This would usually explain why it works on manual but not on auto (I assume you mean the focus setting and not the camera's modes). If you're still having issues I recommend you contact a nearby Nikon authorized service center for assistance and possible repairs. Hope this helps!

Hiram
Photo Tech Repair Service
110 East 13th Street
New York, NY 10003
212-673-8400

If it is a auto focus lens the lens should be serviced and cleaned. If an auto focus lens gets dirty it gets stuck.

You need to have a compatible lens to be able to autofocus. Some older Nikkor lenses and even more so 'generic' lenses (ie. Tamron, Sigma, Opteka etc.) do not autofocus or can be used with Nikon bodies.

Check that the lens is compatible with your camera.

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 : -)

needs repairing at a qualified shop
when was it last cleaned or serviced ?
if you think the camera is worthy, since its old how much is it worth to you vs a new one

theres a little switch to the right of the viewfinder, try moving it

Curious, Have you tried another AF lens on the N55?

I found a notice put out by Nikon, there is a mechanical problem with the Auto focus. U can google it and there is a form to download and print to send in with your camera. The service is free to fix it since it is a manufacturer's defect.

http://www.nikondigital.com/main.html look at the service advisory link on the bottom right. It pretty much describes your problem, same model. you are eligible to a free repair. Good luck