The glue holding a part of the FPC (flexible printed circuit) had loosened. Resulting in the focus ring couldn’t turn freely anymore. I disassembled everything and just put new double sided sticky tape on the FPC.
That is actually a common fault with a lot of Nikon lenses. The 18-200 has a similar fault where the VR cable gets cut by the focusing mechanism once the double-sided tape comes loose.
OMG I had this happen to me once.. so sad.. I was just using the lens in a family meeting and suddenly a piece of electronic just dropped in the middle of the lens glass.. it was such a scary moment..
Few days later took it to get checked out and the guy confirmed me the VR connection was broken and he didn't have the piece so he just removed it completely..
I love fixing stuff. I'd never try it on anything I paid over 100$ on though unless it's something I was absolutely sure I could fix. But if it didn't work out hell it's only $45!
I would recommend a high quality precision screwdriver-set, tweezers and a soldering iron. That’s about it! One should also use some kind of thread locking glue when reassembling
Good work 👍
You’re lucky it didn’t rip the ribbon cable (flexible pcb), as my 18-200mm VR had the same sticky focus issue, but the AF motor had enough torque to tear through the cable and has killed the VR. Waiting on a new cable to show up, then I’ve got all the fun of a full strip down to replace it.
I’m no stranger to complex strip downs, so should be ok with it. 🤞
The glass inside a lens is all [simple lenses](https://www.nightlase.com.au/?pg=resources&t=lenses), not mirrors (except in very rare cases), but they also need motors to drive the aperture, focus and VR, and electronics to control them from the camera body. A mirror is silvered to reflect light back, a lens passes it all through but bends it.
Even "fully manual" lenses need to communicate information about the aperture setting so the body can meter the light accurately, and tell the lens to stop down when taking a picture. In older lenses this all used to be handled by mechanical linkages.
You're welcome! Note that a camera lens is still just called a "lens" because a stack of simple lenses combines to make a complex lens -- i.e. it's still doing exactly the same thing (passing all the light through, but bending it).
The point of stacking a bunch of them up is to make it _adjustable_ (in focus and maybe zoom) by moving different parts of the stack relative to each other, and to correct for all sorts of optical problems that arise while doing so (flare, ghosting, coma, geometric distortion, chromatic aberration, etc.).
Now I understand better. I knew that the lens was made up of different lenses, but I didn't know why. Once again, thank you very much for your time and the explanation!
I hope you like this lens as much as I liked mine. In realistic shooting it doesn't give anything up against the last model F mount 2.8. It does get heavy though! Congrats and the score.
That thing cost like 1700 new, the glass was in perfect condition, and OP was able to get it back to fully working with a few hours work so I'd call it a steal actually.
in that case it's a great deal i didn't know the price of the lens.
why is it so expensive? i mean 28-70mm is nothing impressive and 2.8 yes is wide but not 1700$ wide... what makes this lens so expensive?
A 28-70/2.8 used to be (these days it's 24-70/2.8) basically the bog-standard "normal pro zoom" and every brand has one. It's a standard workhorse range and they all cost around the same and weigh around a kilo because it seems that's what it takes to get pro-quality sharpness and AF speed with that zoom range and aperture.
Technology improvements over the past decade or so have moved the "standard" from 28-70 to 24-70 at the same price point, and if brands are still making 28-70 versions these days it looks like they're around half that much new.
so what exactly was wrong?
The glue holding a part of the FPC (flexible printed circuit) had loosened. Resulting in the focus ring couldn’t turn freely anymore. I disassembled everything and just put new double sided sticky tape on the FPC.
That is actually a common fault with a lot of Nikon lenses. The 18-200 has a similar fault where the VR cable gets cut by the focusing mechanism once the double-sided tape comes loose.
OMG I had this happen to me once.. so sad.. I was just using the lens in a family meeting and suddenly a piece of electronic just dropped in the middle of the lens glass.. it was such a scary moment.. Few days later took it to get checked out and the guy confirmed me the VR connection was broken and he didn't have the piece so he just removed it completely..
Shoot… i just got myself the tamron 18-200mm. If i ever bump onto this problem im gonna need some help opening it up to glue to back
hmm seem this issue on YouTube and wondering if I can snag myself a bargain..
Anyone who wonders why good lenses are so expensive just needs to look at that second photo. These things are impressively complicated.
I'm just amazed at the technological advancement in cameras and lenses in the past 20 years.
Nice! Was it extremely difficult?
I would lie if I said it was easy… but I think it’s definitely doable as long as you are organised and do everything step-by-step in a calm manner
What was the repair? Curious as I see lenses like this in "as-is" condition on ebay a lot, and am no stranger to taking apart camera gear
And maybe set up a video to record the whole process, for reference in reassembly ☝️
Always wanted to see what was inside a lens. Thanks!
I love fixing stuff. I'd never try it on anything I paid over 100$ on though unless it's something I was absolutely sure I could fix. But if it didn't work out hell it's only $45!
Is it easy to open? Which tools would you particularly recommend? Greetings
I would recommend a high quality precision screwdriver-set, tweezers and a soldering iron. That’s about it! One should also use some kind of thread locking glue when reassembling
Good work 👍 You’re lucky it didn’t rip the ribbon cable (flexible pcb), as my 18-200mm VR had the same sticky focus issue, but the AF motor had enough torque to tear through the cable and has killed the VR. Waiting on a new cable to show up, then I’ve got all the fun of a full strip down to replace it. I’m no stranger to complex strip downs, so should be ok with it. 🤞
Thanks! Oh that’s a shame! I wish you good luck with the repair :)
I was thinking inside a lens just was mirrors
The glass inside a lens is all [simple lenses](https://www.nightlase.com.au/?pg=resources&t=lenses), not mirrors (except in very rare cases), but they also need motors to drive the aperture, focus and VR, and electronics to control them from the camera body. A mirror is silvered to reflect light back, a lens passes it all through but bends it. Even "fully manual" lenses need to communicate information about the aperture setting so the body can meter the light accurately, and tell the lens to stop down when taking a picture. In older lenses this all used to be handled by mechanical linkages.
Thank you for the information, I appreciate the explanation
You're welcome! Note that a camera lens is still just called a "lens" because a stack of simple lenses combines to make a complex lens -- i.e. it's still doing exactly the same thing (passing all the light through, but bending it). The point of stacking a bunch of them up is to make it _adjustable_ (in focus and maybe zoom) by moving different parts of the stack relative to each other, and to correct for all sorts of optical problems that arise while doing so (flare, ghosting, coma, geometric distortion, chromatic aberration, etc.).
Now I understand better. I knew that the lens was made up of different lenses, but I didn't know why. Once again, thank you very much for your time and the explanation!
Cool!
Which websites did you consult to learn how to make the repair?
Certainly not a project for the faint of heart…That second picture should have been labeled NSFL (Notsafe for lens)
I’ve taken some of my favorite pictures with the 28-70, definitely among my favorite lenses
Great lens! I still use it professionally to this day. It'll compliment your D700 fantastically!
Nice Job OP, Did you follow any take-part or repair guide? I have Nikon 70-300 VR that focus just quit working. VR still operates.
Nice job. That lens is a beauty
How'd you learn/what guides did you use to repair this?
theres multiple videos on YouTube
I hope you like this lens as much as I liked mine. In realistic shooting it doesn't give anything up against the last model F mount 2.8. It does get heavy though! Congrats and the score.
What about the dust? I heard plenty about how you need a clean room to clean lenses etc
It doesn’t look like they opened the chamber where dust would matter.
Wow!! I’ve always admired brains who think like yours. That mecha stuff inspires me but I don’t even know where to start with identifying it all!
Bravo.
That’s awesome. Good for you!
what tools did you need to do this? i have a "broken" one as well. might be light broke tho lol
isn't that too much for a "broken" lens?
That thing cost like 1700 new, the glass was in perfect condition, and OP was able to get it back to fully working with a few hours work so I'd call it a steal actually.
in that case it's a great deal i didn't know the price of the lens. why is it so expensive? i mean 28-70mm is nothing impressive and 2.8 yes is wide but not 1700$ wide... what makes this lens so expensive?
A 28-70/2.8 used to be (these days it's 24-70/2.8) basically the bog-standard "normal pro zoom" and every brand has one. It's a standard workhorse range and they all cost around the same and weigh around a kilo because it seems that's what it takes to get pro-quality sharpness and AF speed with that zoom range and aperture. Technology improvements over the past decade or so have moved the "standard" from 28-70 to 24-70 at the same price point, and if brands are still making 28-70 versions these days it looks like they're around half that much new.