D4s AF stopped working - help needed.

helipilothelipilot Posts: 8Member
edited December 2018 in D3/D4/D5
The issue: I am using a Nikon D4s and all of the sudden, none of my lenses will autofocus in the viewfinder mode. It maxes out and then comes back to infinity. So every time, the background basically focuses but not the subject. However, in live view mode, it focuses flawlessly and sharp. I do not have this issue in my Nikon D7500. Any ideas why it won’t work unless in live view? I have checked all of my AF settings and it’s the way it needs to.

Just to clarify.
1: All of the standard checks for auto focus issues have been done.
2: All Nikon and Sigma lenses did work before, none will now (when in auto using viewfinder).
3:All of these lenses work perfectly on my D7500.
4: My original guess is maybe the Phase Detect Autofocus Sensor? But don’t know how to go about checking that.
5: still works in manual mode and auto when using the live view.
Post edited by spraynpray on


  • Ton14Ton14 Posts: 698Member
    edited December 2018
    That's a disaster, the camera is useless then.

    When you autofocus and get a sharp photo it must be the viewfinder.

    I had that once when I hit the table with my D600, went to Nikon service Center and it was a small pin in the viewfinder that was damaged and not expensive to fix.

    PS. the table was fine.
    Post edited by Ton14 on
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  • daveznspacedaveznspace Posts: 180Member
    helipilot said:

    The issue: I am using a Nikon D4s and all of the sudden, none of my lenses will autofocus in the viewfinder mode.

    1. Did you blow out the af sensors in front of the actual sensor with a rocket blower?
    2. Did you clean the contacts on both the camera and the lenses? I use eclipse sensor cleaner on a lint-free microfiber cloth. You can also use 99% isopropyl rubbing alcohol (no pencil erasers or cotton balls or qtips)
    3. Clean the metal mounts on both body and lenses as well, every time you put them on or take them off (lenses) they leave little fragments of metal shavings.

    I'd start there and see what happens

  • spraynprayspraynpray Posts: 6,545Moderator
    I have changed the title of this thread to make it usefull for others to search for help later.
    Always learning.
  • DenverShooterDenverShooter Posts: 416Member
    Do a full factory reset...

    Denver Shooter
  • daveznspacedaveznspace Posts: 180Member
    it's trashed!! send it to me :p
  • helipilothelipilot Posts: 8Member
    Thanks gents.
    I did blow out with the rocket blower.
    I did a factory reset.
    I cleaned the contacts.
    I’m waiting for the sensor cleaning kit to come in tomorrow to clean the sensor. I want to do it right haha.
  • helipilothelipilot Posts: 8Member
    I’m very bummed about it. I’m not going to lie, I did do something risky today, just to try it. I had a family photoshoot to do today. Rather than using my backup (D7500), I used the live view to take all of the photos. They turned out better than when I use the viewfinder haha. I have always noticed that the focusing is better with the live view, but obviously it’s not practical and it’s slower. But it worked out well.

    After I clean the sensor today with the sensor cleaning kit, if there’s no luck, I suppose I will have to send it in to a professional.
  • spraynprayspraynpray Posts: 6,545Moderator
    Sounds like a plan. Fingers crossed.
    Always learning.
  • Ton14Ton14 Posts: 698Member
    As I said, when the photo's are sharp it cannot be the sensor of course, it is just the viewfinder.
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  • helipilothelipilot Posts: 8Member
    Isnt it two separate sensors for the viewfinder focus and the live view focus? Or if it’s as you say, the viewfinder. Where do you recommend I check next?
  • Ton14Ton14 Posts: 698Member
    We have, as far as I know, optical viewfinders ( Eye-level pentaprism single-lens reflex viewfinder), what you see is what you get, that's why we need a mirror. Your sensor and the system is fine, because you get sharp photo's with AF.

    What I should do is a check by a Nikon service centre. Here in Holland the price for that is € 45.- then you know exactly what the problem is and how much it will cost.
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  • helipilothelipilot Posts: 8Member
    That makes sense, thank you. I will probably be sending it in Wednesday
  • Ton14Ton14 Posts: 698Member
    Oh, a couple of years ago I updated my house insurance with:

    Valuables Outdoors for € 7,55 per month.
    Insured amount: € 5.000, -

    Everything (not only photo stuff) is assured for stealing, accidents etc. even when it is located in my car.

    Somewhere on this forum is a big thread about insurance, look it up.

    Last month my 24-70mm f/2.8 dropped from the table (not at home), focus was only blur and my € 2000.- lens was useless. Nikon fixed it, cleaned the lens for € 489.-, paid by this insurance and this 10 year old lens works as new again. I had to use this insurance in the last years 3 times already for a total of € 1600.-

    Insurance gives me a very relax feeling, when I walk around.
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  • CaMeRaQuEsTCaMeRaQuEsT Posts: 357Member
    edited December 2018
    The problem must be the PD AF sensor located underneath the mirror box is not getting an image from the lens, either because the 2nd mirror is out of alignment or stuck in its retracted position or because the flap that covers said sensor when the mirrors are up is stuck in its closed position. Either way, you need to send it in.
    Post edited by CaMeRaQuEsT on
  • helipilothelipilot Posts: 8Member
    Well, the sensor cleaning kit came in a day late. Just cleaned it very carefully and properly, no luck. Tomorrow morning I will be taking it to a place about an hour away to have them check it. I will update on the results.
  • helipilothelipilot Posts: 8Member
    Turns out it was the Autofocus Shield baffel on the bottom of the mirror box. It’s broken. There’s a couple of little pins that hold it in place, one of them is broken off. Off to Nikon it went. And the technicians work for a very good and large company in Austin Texas, they said they have never heard of this happening before. And my camera was never dropped... how annoying. After it’s fixed, I’m selling it and moving on to the Sony Aiii mirrorless. It’s way smaller and lighter and generally better. But I’m keeping my D7500 and a few of the Nikon lenses.
  • mhedgesmhedges Posts: 2,881Member
    Well at least consider the Nikon Z series. Especially if you will be holding onto some Nikon lenses.
  • helipilothelipilot Posts: 8Member
    I thought about the Z7, but I’m still feeling the A7iii will be a better fit. I don’t know. I’m still weighing the options.
  • spraynprayspraynpray Posts: 6,545Moderator
    @CaMeRaQuEsT gets the prize for correctly diagnosing the problem area. Well done.
    Always learning.
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