D800 aperture ring on camera malfunctioning

Camera in decent shape; shutter at ca. 15k. I only use manual (Nikkor AI, etc.) lenses (though have one G lens I could test with).

 

Camera got a bit wet in rain a week ago for ~60 mins; possible some water seeped in minimally around buttons, etc. but not to the extent that water was inside on mirror, shutter, displays, etc. Just a rain soaking (mostly of me) as has happened now & then.... Camera was working great before (& during) the rain, then dried off with towel (camera then me) & a while later did a check and error appeared.

 

After letting the camera dry, the aperture registered on camera (top & viewfinder; rear too I suppose) is way off - with lens on or off the display registers f5.6 (or 45 if lens on) then with only a short turn of aperture ring on camera, to f64. No 'intermediate' values. (This also called 'Meter coupling lever' in one manual). Camera has had plenty of time to dry by now... Seems to be error in sensor actuated by camera's lens coupling ring (which feels as it always has).

 

There are no 'error codes' displayed, just a very wrong aperture indication from the AI ring on the camera (I did one fast experiment on manual and was able to make a decent exposure despite the incorrect aperture reading, but usually use aperture priority auto as basis for exposure).

 

Have tried different lenses, removing battery, etc. with no change.

 

Anybody have advice on what this might be? If needed, what are recommended repair places these days for this sort of thing?

 

This camera does all I need for a Nikon digicam (even just finally got my Di-GPS going, which is great!) so hope problem is fixable... Luckily I brought my Panasonic GX85 along this expedition as backup... but a poor substitute for the Nikkor lenses!

The meter coupling lever above the bayonet mount should be at the 1 o'clock position when looking from the front - is it? You say with the lens off, the top LCD display reads f/5.6 - it should read f/1.2 (but that could depend on which lens is currently active in the non-CPU lens menu). The lever is spring loaded - pushing it counterclockwise (looking from the front) should change the reading of the aperture on the top LCD; releasing the tab, it should spring back to its start position. Is there resistance (some is normal) when the lever is moved? Does it indeed spring back when released? I assume the design of what's behind that lever hasn't changed over the years - then there's a thread that connects the lever to a brush/coupling gear combo connected to an FRE inside the camera - should be safe from moisture but who knows without actually checking.

1 o'clock position when looking from the front - is it?

Yes.

 

Is there resistance (some is normal) when the lever is moved? Does it indeed spring back when released?

Yes

 

All appears and feels as normal - except the aperture signal the camera receives...

 

However - I did just fiddle with various non-CPU lens sets and found that the 'range' of the incorrect aperture readings varies by that - e.g., a 1.8 lens goes from 22-32, while a f4 goes from 45-64... commensurately variable range with lenses off, the range depending on widest aperture in non-CPU setting.

Here's an image of what's behind that follower tap: nikon fe resistor ring / meter coupling. Sometimes, dirt gets in and causes malfunction - often remedied by exercising the ring. Not sure that would work in your case - though I don't know what causes the apparently wrong registration of aperture values you are experiencing.

 

When you move the ring manually (either with a lens attached or without), the LCD on top of the camera should go through the range of apertures - not just display one or two values (that are one stop apart). For an f/1.8 lens, the LCD would show f/1.8, then f/2, f/2.8, f/4 and so on until f/32 when the aperture follow tab has completed its trip and is at about the 11 o'clock position). What you are experiencing could indicate that the string/cord got dislodged - but that's just a guess on my part.

A friend of mine once drowned his D3 on a very wet shoot and the main problem was the aperture follower. Water had got into the slot and messed the resistance track.

 

It took repeated scary 'douches' with IPA.... until it finally returned to normal. Worked for the next 2 years flawlessly.

Hmm, that looks like a fine precision bit, esp. the string, that might be affected by the wet (but not so wet as a dunking, just shooting in the rain as I've done before of course - best light!).

It seems to go from the wide to smaller aperture (e.g., 45 to 64) almost instantly, as in one minute of rotation, though if I try super slow I can sometimes see some indication of a 'middle' ; e.g., 5.6, 45, 64 (with lens off).

I'm not experienced with camera repair other than door seals, etc., so a bit wary of trying anything myself.

Should I send it to Nikon, or might another repairist do a good job?

 

(I got this reply from Midwest Camera Repair today: "I would send to Nikon, it may need a main circuit or other circuit parts.")

Nikon Authorized Photo Services (APS) https://www.nikoncamerarepair.com/ or keh spring to mind.

 

I wouldn't attempt the repair myself either - looks like it's quite is to mess things up even more.

I wouldn't attempt the repair myself either - looks like it's quite easy to mess things up even more.

 

Although, to be sure, if Nikon hasn't simplified the Ai mechanism from that Rube Goldbergian contraption in the FE, they absolutely need to be sued for engineering malpractice.