Difficulty

Moderate

Steps

2

Time Required

                          15 minutes

Sections

1

  • Repairing Nikon D3100 Autofocus
  • 2 steps

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Introduction

What you need

Step 1

              Repairing Nikon D3100 Autofocus
  • The problem is that the autofocus can not adjust correctly. There can be more than one solution.
    1. Try forcing the lens to rotate a fraction of a inch. This will sometimes help the problem. Or simply move the switch from M to A on the lens.
    1. Try to switching to a single of the 11 auto focus points. Then try if there are specific points that are the problem.
  • This is done by selecting in the menu of your camera to the points. Then focusing on a single object with a background far away. Try focusing on the object then on the background. If this is possible the autofocus point is fine.
    1. If all auto focus points are fine, try updating the firmware or cleaning the sensors inside the camera behind the mirror. If a one or more points are out of order, also try cleaning the sensors behind the mirror.
    1. Detatch the lens from the camera, by applying pressure on the release button and twisting the lens so it can be released. See picture
    1. Set the camera selection wheel to manual (M), see picture
    1. Turn the camera on, and start the liveView format. This will flip op the mirror inside the camera.

The problem is that the autofocus can not adjust correctly. There can be more than one solution.

  1. Try forcing the lens to rotate a fraction of a inch. This will sometimes help the problem. Or simply move the switch from M to A on the lens.

  2. Try to switching to a single of the 11 auto focus points. Then try if there are specific points that are the problem.

This is done by selecting in the menu of your camera to the points. Then focusing on a single object with a background far away. Try focusing on the object then on the background. If this is possible the autofocus point is fine.

  1. If all auto focus points are fine, try updating the firmware or cleaning the sensors inside the camera behind the mirror. If a one or more points are out of order, also try cleaning the sensors behind the mirror.

  2. Detatch the lens from the camera, by applying pressure on the release button and twisting the lens so it can be released. See picture

  3. Set the camera selection wheel to manual (M), see picture

  4. Turn the camera on, and start the liveView format. This will flip op the mirror inside the camera.

1024

Step 2

  • Take a dry can blower. Or if in lack, use an empty plastic bottle, without moisture inside, and use it to blow on the autofocus sensors.
  • They are located at the bottom under the mirror. NOTE Do not blow with your mouth, small amount of moisture will hit the CCD also located here.
  • Turn the camera off
  • Reattach the lens. Push the lens, white point to white point and turn the lens in place.
  • This worked for me, hope it also helped you ;)

Take a dry can blower. Or if in lack, use an empty plastic bottle, without moisture inside, and use it to blow on the autofocus sensors.

They are located at the bottom under the mirror. NOTE Do not blow with your mouth, small amount of moisture will hit the CCD also located here.

Turn the camera off

Reattach the lens. Push the lens, white point to white point and turn the lens in place.

This worked for me, hope it also helped you ;)

Hope you could use this information

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                                                                                      25 other people completed this guide.

Author

                                      with 4 other contributors 


                    Lasse Lorenzen

Member since: 02/19/2013

830 Reputation

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coleman corrigan - Dec 27, 2013

Reply

wow! good tip, AF appeared broken on my D3100, detach and reattach lens did fix it !!

Mithlesh Shrivas - Apr 10, 2016

Reply

My camera fell on the concrete floor 2 times within 10min..thanks to my little devil..the autofocus wasn’t working. I was hopeless and thought of contacting nikon service center and the I searched for some repair tips and came across this page..wow. …it worked for me as well..thank you so much..you saved me a few good bucks for sure..more than that I’m having a trip after a week and wasn’t hopeful to get it back..but I’m a happy man now and I’m noy mad at my little angel now :)

Lasse Lorenzen - Apr 11, 2016

Hi Mithles Shrivas

Happy to know that it worked :) I know the problem with the small ones, have 3 my self :)

have a nice day :)

Tom Hallman - Jun 19, 2016

Reply

Yes!! Thank you so much. The center point of our autofocus wasn’t working, and I was worried that the camera would need expensive repair. This did the trick instantly. You just made my day!

Kolby - Sep 20, 2016

Reply

My manual focus does not even work? I guess I have to have it repaired? It just stopped working one day.