Intro: How to Fix Stuck Zoom Ring on a Tamron 17-50 2.8 Non VC Canon Lens
So your poor Tamron lens won't zoom anymore? Don't fret, it can be fixed if you have the guts. My lens is outside the 5 year warranty, check yours first.
Let's just start taking this thing apart and see what the problem is. My lens was jammed in a way that I could barely get the zoom to do anything. If you are in the predicament, DO NOT FORCE IT! You will damage the ribbon that transmits info about where the zoom is to the camera (like I did). I am only going to show how to fix the jam, the ribbon cable is a whole issue that I will not be going into here. Basically, my lens always shows 32mm as my zoom setting. This give bad info in my exif data, and causes auto zoom flash heads to not move with your lens. If that is a deal breaker, Tamron has excellent technicians who will happily charge you many dollars to correct the problem, and give you a warranty on the work. We are going to void the crap out of our warranty!
- Read all the steps first
- Take your time
- This is just a guide to how MY lens broke, YOUR lens may be different. I have fixed a couple lenses with the same problem, ended up with the same fix. Your mileage may vary
Step 1: Remove Screws From the Mount
Start taking out screws. Keep track of them of course, and only remove the ones circled in red.
Step 2: Removing the Mount
Lift up gently on the silver mount on the side opposite of the contacts (there is a short ribbon behind it) and then push the black center out from the backside of the mount while holding the silver towards the lens. It takes a bit of a push, but it will just pop out.
Step 3: More Dissasembly
On the top now should be a few copper colored "C" shaped rings with a black plastic one on the bottom of the stack. Pay attention to that little notch, it will help you put it back in place when this is all done.
Remove the two screws holding the logic board in place, disconnect the ribbon cables. For the black connectors, pull the brown part out away from center slightly to allow the ribbon to slide out. For the white connector, flip the brown flap upwards from the cable with a wide spudger tool gently. Then gently remove the board and set it aside.
Start removing the six screws holding the next part in place, notice how one of them is a different size that the others. When I took them out I made sure to work around the lens in order, being sure to mark which spot I started so they would all go back to the same location.
The next piece is a small guide that needs to be removed. Notice the little notch at the end, there is a copper colored peg inside the lens that will slip through there when you remove the T-shaped piece and when you need to put it back in.
Step 4: We Can See the Problem Now!
If you look down inside the lens, there is a tiny grey bracket with a tiny silver screw. That screw is loose! If you jiggle the zoom, you should see it wiggle a little bit. This is causing the jam. We need to gain access to it.
If your zoom ring is not lined up with the zoom markings, now is the time to fix it. Simply press with two fingers at 9 and 3 o'clock, with the loose screw at 12, and turn clockwise until it is in the right place (holding the base with your other hand), turning about a quarter inch before resetting your grip to 9 and 3. You are basically deforming the outer ring so it will rotate independently of the zoom mechanism. There should be a slight bump when it lines up correctly, you cannot adjust it once we get the screw tightened.
Now the hard part starts. Time to remove the next ring portion of the lens. There is a small metal bracket that attaches to the M/AF selector, bring the opposite end up and gently work the M/AF bracket away from the center. We just want to get in loose so we can move it enough to access the screw. BE CAREFUL not to rip or pull on the ribbon cable circled in red. If you can zoom your lens to 17mm there will be a bit more slack to work with.
Step 5: Tighten That Screw
Turn the ring we just loosened just enough so you can get your screwdriver in there and tighten up that darn screw. Notice we don't remove that whole ring, just move it slightly out of the way. You should now be able to work the zoom ring without jamming.
Step 6: Let's Put It Back Together! "The Hard Part"
This part is tricky so take your time or you will have a bad day. To get that ring back in place, we need to put the M/AF focus bracket back in place. That little hook needs to go UNDER the gear circled in the photo and the notched bit needs to surround the blue switch. I found that putting the blue switch up and the outside switch down helps. Use a spudger or tweezers to push the gear up (towards the base) and wiggle the zoom ring slightly and it will stick, but only just. This step will test your patience. You'll know the bracket is back in place correctly if the black outer ring sits flush. If there is a gap, try, try again. You can do it! Once you have it back in place, put the six screws back where you found them. Then replace the T-shaped guide, remembering to get the peg back in the groove.
Step 7: Final Reassembly
Let's put the circuit board back in. I found it easier to get the two ribbons that are close together reinserted before I got the board in place. That one ribbon is short, be gentle. Once you get the two settled, find the little hole with the peg it sits on (if you notice at the end your mount doesn't sit flat, you messed this part up like I did). Then move the rest of it in place, being sure the little notch I circled finds the proper home in the outside ring, or it will not line up. Replace the screws from where you took them and reinsert the last ribbon cable.
Remember that little tab for the "C" rings? Line up the black one, then the copper ones.
Place the silver ring back in place (it only goes one way with all the screws lined up), replace the screws, the contacts should be made to sit against the ring in such a way that it doesn't move.
Push the black inner ring back into place and secure the last two screws. Check that the mount looks flat and even around the entire lens. If it doesn't, you probably didn't get the board in place correctly, go back and fix it.
Mount the lens to your camera and check functionality. You will probably notice that the lens no longer gives correct zoom info anymore (mine always says 32mm). This is most likely an issue further inside the lens that I recommend you send away for repairs if it bothers you. I was not able to find, with certainty, the proper cable required.
I hope this helps and fixes your problem, remember to clean the lens elements after as you will certainly smudge the glass a little.