Triangle F0 on a Nikon d7100

[Brendo09]

My d7100 fell about 4 foot, and landed on it's battery pack (with the metal mounting bracket around it).

When I picked it up, the lens had slightly disassembled at the mount. It's a Tamron 17-50 f2.8 (non VC model). The metal mounting ring had pulled up from the lens barrel, and pulled some screws. I tightened them back up, but the camera gives me an error of Triangle (or delta) F0.

I've pulled the back mounts off the lens, cleaned it up, put everything back how it was. It's tight, but still no change. The error message is still there.

I've tested other lenses, it's just this one that gives the error (which was a big relief).

I can replace the lens with another second hand one for $200, I'm not too concerned about having this one professionally fixed.

Does it sound like something that I can fix anyway? Pulling the mount end apart showed nothing that looked odd. The pins are all out and move freely, so I'm assuming it's a cold solder that's pulled apart in the shock of being dropped.

[arthurking83]

F0 means no aperture reading.
You'd get that if you mounted a manual lens(ie. no CPU/electronics) and didn't register any lens types in the internal database.

Those lenses tho have an aperture indexing cutout on the mount, which then couple to the corresponding tab slidy thingy on the body.
On the manual lens as you close down the aperture, the ring on the lens turns, and moves the aperture indexing tab on the camera body, and hence the camera knows what apertuere to stop down too when it fires off it's shots.

On the Tamron lens tho, it's a CPU lens, so it doesn't have(or need) the aperture indexing cutout(ie. it has no manual aperture ring). So my best guess, is only going to be a wild .. possibly maybe type of guess .. but does the aperture lever on the lens move freely.
if you don't know what that is< and you should if you've pulled the lens mount apart a little .. it's a small exposed prong like metal thing.
If you expose the rear glass, hold the lens so that you're looking through the rear element and out into the wild blue yonder, AND with the CPU contacts at the 12 o'clock position, the aperture lever is at the 2 o'clock position.
You can(safely) move it with your finger(no damage will be done). You push it upwards or anticlockwise towards the 12 o'clock position, and it should spring back instantly to it's normal 2 o'clock position.
if there is any binding feeling at all, there's a problem. As you do push it, look INTO the lens and watch to see how the aperture blades move. They're also quick responding, and should immediately reflect the movement of the aperture lever.
Again, any delay between aperture lever and aperture blades = a problem.

I've never pulled one apart to see 'what's what', but I'm assuming that there is going to be a wired connection between the contact pins, and the actual CPU, and or focusing/zooming mechanism.
If there are any wires and the lens slightly disassembled at the mount, maybe a wire has been pulled too far, off it's solder joint, or broken .
They are a very light gauge wires(if any).

Hope that helps, and be sure to post back with any fix, or images of the internals of the lens if you can. (do you have a macro lens?)

[Brendo09]

I've found the aperture thing, it's fitted into the sleeve to shif the aperture ring in the barrel. It moves freely, opens and shuts as you shift it.

One thing I'm curous about is below

DSC_0277 by Brendan Webb, on Flickr

On right under the metal mount ring is an electronic ribbon. It has what appears to be oncovered contacts, however it has no mounting place I can see within the barrel of the lens. There is a contact joint here

DSC_0278 by Brendan Webb, on Flickr

but there's nothing to clip into.

Does that help? My only thought is that the ribbon from the mount should be attached to the mount via a glue or heat treatment, and it's broken free now.

[ameerat42]

Brendo. -- Or held in by friction?

[Brendo09]

But it didn't reach by friction. and even if it did, that's easy to dislodge with a bump.

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[ameerat42]

OK. It just looked like a possibility.

[arthurking83]

ps:
Curiosity got the better of me!
So had to have a looksee, and there are no wires as such, but a slightly more flexible flex cable(than I've usually seen) .. so it's almost cabled, but not(if that makes sense).
CPU contact block(pin block if that makes more sense) is flex cabled to the CPU board, and hard soldered(bad design!!), so maybe you're right, that a solder has come loose, or possibly the flex cable at the contact block end has torn.
If the solder, then if you can resolder .. I reckon you'd have some luck fixing it up.
If the torn flex cable at the contact block end .. I doubt it, unless your very good with electronics(ie. make your own PCB boards and suchlike).
I do remember a paint on product that is used to pain trace electrical routes such as those on the flex cable .. can't remember the brand or product name tho. No idea on what type of brush woudl be needed if you do locate such a product tho.
(I used it a zillion years ago to fix a broken flex connection on the back of an instrument panel(auto) but those flex lines were close to 2mm wide, so much easier to 'pain this product on'.

Question is do you have the required tools to get the screws off .. and don't say you have a jewlers screwdriver set, as they will do more damage than what's already done to the lens.
The screws used on Japanese lenses aren't Philips, and never use Philips screw drivers on them if you want to get them off and then back on again!
The screw drivers you NEED are JIS(Japanese Industrial Standard) impossible to find in Aus, but can be found in many online type stores. I got mine from ebay, from a seller in Darwin(of all places).
Very nice kit, and the screwdriver sizes you'd need for this particular lens are J000 and J00.

if you're willing to give it a go, I can PM you the details of the actual screw driver set I got. Cost me about $20ish or so .. maybe less. Nice handle and nice quality driver heads too.

Now to really put you off trying:
The screws that hold the contact block and rear baffle need to be ordered, 3 different sizes so put one in the wrong location could be damaging to lens.
The 3 mount screws are easy and need no care .. but! be careful on how you remove the rear mount. I was(but not enough) and the screw slot for the AF fell out of place. After a few minutes it was obvious as to where and how it's supposed to be located, but an interesting experience hearing a faint tingle tingle as the gear-screw fell sight unseen under the mount.
Then you have the copper shims to be weary off, that they don't fall out and you lose the sequence they're supposed to go back with .. AND of course the need to hold the aperture lever in the correct loication as you assemble the mount back onto the back of the lens.
As you remove the mount, the aperture will spring to different location to what it is when the lens is all together. Not hard to do(put it back) just need to be understood as you try to carefully place the mount onto the back of the lens.
if you don't hold the aperture lever it won't sit, hold the aperture lever in the correct place, and the mount sits nicely. once the mount sits nice and the AF screw is located correctly you can let go of the aperture lever again .. and then breathe!

Pulling apart and putting together is not difficult, it's best described as a game of patience. You also need good eyesight to see the impossibly small J000 screws too!

[Brendo09]

What order do the shims go? They went all over the place.

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[Brendo09]

And I've come to terms with it being knackered. This is all just curiosity from here on.

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[arthurking83]

And I've come to terms with it being knackered. This is all just curiosity from here on.

.....

That's the attitude to have.

Order of shims(I guess) will be lens dependent. So my lens will be different from yours, and the shims and numbers of them will be different.

Do you have a multimeter?
If so, does it do continuity tests?
If so, you'd want to check the continuity between each silver contact spot and the flex cable at the solder points.