I'm having this intermittent problem that the camera does not want to focus in auto-focus. When this happens I try to switch to manual on the lens, (both 300mm, and 55mm) but the toggle button will not budge. I have to wait about 1-2 mins sometimes longer before the auto-focusing works again.

Also, I get either r08, r24, r200 showing up on the bottom right of the screen - apparently this has to do with buffering. My card was empty, lighting was great. I got the camera end of January 2013, and all was well until the beginning of March.

I did a "reset setting" thinking maybe I had set some setting that would cause this - but this didn't seem to be the case. I am using the same card I always did. Just wondering if I need to take it to the doctor's

2 Answers 2


Well, the fact that you have the same problem with two different lenses would seem to make it unlikely that it's a lens problem.

On the other hand, these will be AF-S lenses since you have a D5100, so the AF motor is in the lens, and you mention the problem where the M/A switch is stuck, which points to the lens(es).

Given you have the errors showing, sounds like a general electronics problem. Seems unlikely to have developed separate issues with AF on two lenses and also something wrong with the card/buffer.

The system reset was a good idea. I'd give the batteries a good charge, do another system reset, then remove the lens, wipe the contacts well, and reseat the lens until it clicks. If you still have problems, the camera is under warranty, have it checked out.

  • Thank you! Best answer if've heard yet! I'll try it and see if that does the trick!
    – user19104
    Apr 2, 2013 at 15:02

You should try it with another lens to see if it is the problem. However, it might depend on how you're using the camera. If there isn't much light, I've found that the D5100 struggles to autofocus unless you use a torch or something similar. Check the aperture it's using. Cameras usually have a problem with focussing when the aperture is below f/8 or so. Finally, it could depend on what you're shooting and the amount of contrast there is in the scene.

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