Canon EF 24-70mm f/2.8 L USM disassembly and replacing the aperture flex cable

This is a video about disassembling the Canon 24-70mm f2.8 USM lens to access the aperture cable. I had this Canon 24-70mm lens which had problems with the aperture. The aperture did not work, and it was caused by a faulty flex cable. So I had to disassemble the lens, replace the flex cable with a new one, then assemble the lens. In this video I'll show you how to disassemble the lens to get access to the aperture unit flex cable.
UPDATES: n/a
TIMESTAMPS:
- 00:00 Intro
- 00:32 Tools
- 01:06 Like, sub, donate
- 01:34 Disassembly
- 22:31 Aperture cable replacement
- 26:21 Outro
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- Canon EF 24-70mm f/2.8 L USM repair hunting focus problem by cleaning the focus strip bar: • Canon EF 24-70mm f/2.8...
- Canon EF 24-70mm f/2.8 L USM assembly after replacing the aperture flex cable: • Canon EF 24-70mm f/2.8...
- Canon EF 24-70mm f/2.8 L USM - how to clean the lens inside: • Canon EF 24-70mm f/2.8...
- Canon EF 24-70mm f2.8 L USM disassembly for replacing the flex cable in the focus motor: • Canon EF 24-70mm f/2.8...
- Canon EF 24-70mm f2.8 L USM replacing the flex cable of the USM motor after disassembly: • Canon EF 24-70mm f/2.8...
- Canon EF 24-70mm f2.8 L USM assembly after the flex cable of the focus motor has been replaced: • Canon EF 24-70mm f/2.8...
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TOOLS I USED (ebay / aliexpress link):
- PH000 screwdriver: ebay.us/Dz8nTA | ali.ski/2e8ZaZ
- PH00 screwdriver: ebay.us/Xo63D7 | ali.ski/ao2sD
- Flat head screwdriver: ebay.us/KxaUDk | ali.ski/ViV00
- Plastic spudger: ebay.us/JQLobF | ali.ski/7RsFU
- Metal tweezers: ebay.us/jGp7JO | ali.ski/g4VpW
- Adjustable metal tweezers: ebay.us/yc3cbb | ali.ski/k_elg
- Wood screw: ebay.us/zty059 | ali.ski/61n7G
- Cutter knife: ebay.us/6etvNf | ali.ski/eRq8mW
- Soldering gun: ebay.us/Byxij4 | ali.ski/KqYjqY
- Soldering iron: ebay.us/OKwNhQ | ali.ski/hI5HS
- Soldering iron (thin, 0.3mm): ebay.us/WhwoFU | ali.ski/4NoYk
- Soldering iron (thin, 0.5mm): ebay.us/BIkd7G | ali.ski/PIx1I1
- Desoldering pump: ebay.us/4rmHRt | ali.ski/NWL7-4
- Permanent marker: ebay.us/GFUtke | ali.ski/HOZKG
- Canon EF 24-70mm f/2.8 L USM aperture flat cable: ebay.us/DMdh2C | ali.ski/tTfcq3

[@photonmaster6162]

You are removing the outer barrel as an extra job for you. It is not necessary, just work from the service holes. Keep the front element's eccentric collar positions with a marker. So you do not have to make alignment. I fixed hundreds of them.

[@CamerasLensesEtc]

I don't really understand that... can you give me some timestamps which parts of the disassembly process can be skipped?

[@photonmaster6162]

@@CamerasLensesEtc Starting from 10:10, the main sleeve will be kept just like that, do not remove other inner barrels. Instead, from the service holes, remove the 2nd group (the part you take out at 19:17) with removing the eccentric collars. Move it out by loosening with your tweezers from the screw holes. Then take out the 3 white collars holding the aperture group, end let it drop on your hand in the barrel. Once you fix the aperture cable put it back, then put the second group back in place (you will need locking tweezers or similar), align the holes, put eccentric collars with screws. (This 2nd group, as you know, will need sharpness alignment after you put all the lens together minus the focus rubber). You are increasing your labor too much by removing inner barrels. This lens and the 2nd model too have a flaw in aperture routing driving design. That is why it breaks down after a number of zoom in/out movements. If you trim the flex cover metal's inner lip, it will not catch the flex cable's curved side and rip it prematurely. That is one of the remedies. On top of all, your videos are good, keep up the good work!

[@CamerasLensesEtc]

@@photonmaster6162 I pinned your comment, so if someone would like to do that, they can follow your instructions. When I will have this lens again, then I'll make a video using your instructions.

[@agoodbogey]

do you still fix lenses?

[@esieyleul2397]

@@CamerasLensesEtcI have one for repair

[@DropDeadFrederick]

THANK YOU for this and the follow-up tutorial. My 17 year old 24-70 is now back in working order with your help. I just sent you a donation as well!

[@CamerasLensesEtc]

I'm glad that my video has helped you, and thank you for the generous donation!

[@babachalu1616]

Thank you for giveaway this information. Very helpful 🙏

[@CamerasLensesEtc]

You're welcome, I'm glad that my video has helped you!

[@mariomuller4075]

Definitely a very professional, precise and easy to follow instruction. The aperture of my lens was not functional anymore even though no error code was shown on the camera (EOS 6D). I replaced the aperture unit following this tutorial (and your assambling video) and finally it is working again. Thanks for that! Anyway, re-assambling was more difficult and it took me two attempts because the secondary aperture fell apart during assembling...

[@CamerasLensesEtc]

Thank you for your comment, and I'm glad that my video has helped you!

[@davidnemeth5765]

Hi, do you need to use any lubrication on the AF ring? Or at any part of the camera? I need to change the aperture cable as well...

[@BOREMLASEM]

Thanks

[@CamerasLensesEtc]

You're welcome!

[@drishemingway8261]

Thank you for this video..I wonder if the same flex cable works to all canon lenses...thank you again...

[@CamerasLensesEtc]

No, it will not work. Lenses have different size and shape flat cables. Fortunately, you can buy flat cables for most of the Canon lenses.

[@hpwan2]

I have its predecessor (28-80mm f/2.8-4), just wondering if that will probably end up having the same issue?

[@ictcamera560]

So I see you marked the brass guides, but how do you know which guide goes in which hole? An did you mark the elements orientation? Try one scribe mark for one guide, two scribe marks for the second guide and three for the third. This does not guarantee the best focus but it gets you very close.

[@CamerasLensesEtc]

What I do is I remove the eccentric screws in an order (from left to right starting from a specific flex cable or a mark) which I remember, place the screws next to them in that order, so I can put them back in their original place.

[@tooby]

I completed your disassemble & assemble videos replacing the aputure housing and flex cable. problem is the lens is still giving a Err 01 on every f stop other than F2.8. It's not my first time jumping into a lens and feel I completed the repair correctly and now i'm unsure what to trouble shoot to find the issue. Can you offer any further advise please?

[@CamerasLensesEtc]

First, I would disassemble the lens until the PCB, and clean the end of the aperture flex cable with alcohol and scratch pen. If that doesn't help, I would disassemble the lens to have access to the other end of the aperture flex cable, and check the connection between the two ends. Also, check it when the cable is bent, and when it is flat. You can try to replace the aperture cable again, or if you can buy the whole aperture unit, you can replace the whole unit with the cable.

[@mouloudilbouche5625]

Hi, very good Video i used it to replace the flex cable of my 24-70mm but the secondary aperture unit was fallen apart and i tried to reassemble it but without success, do you have any idea on how to reassemble it? thanks

[@CamerasLensesEtc]

Really hard to do that, which I can't explain in comments. I would check if there is any for sale on ebay, it would be easier to buy one instead of rebuild.

[@mariomuller4075]

If the problem still I exists: I just had the same issue. Unfortunately I have not taken a video, and I will never try to do that again: There are two rings, one with holes and one with grooves. I first took the ring with the holes. I placed all 8 blades onto the ring, each with the pin into a hole. All blades need to be aligned exacly into the same direction, creating a circular aperture, which should be slightly closed. I placed a round piece of cardboard into the center of the ring so that the pieces don't collapse.The last blade needs to go underneeth the first one. Once all parts are positioned symmetrically you I placed the upper ring (the one with the grooves) onto the ring where you have arranged the blades. Initially, there was a gap. This was now the tricky part: the upper pin of each blade needs to go into the groove of the upper ring. I managed it by very slightly re-positioning the other blades after the first one or two blades fitted. No force, not pressing. After a while, all upper pins were in their respective groove. The gap between the two rings was now gone. I could close the mechanism by holding the lower ring and rotating the the upper ring clockwise. The blades will open and close by rotating the two rings against each other, but if you go beyond the small resistance, then it will fall apart again... Good luck!

[@pieciak]

@@mariomuller4075 Could you draw it somehow? maybe in paint, because I have absolutely no idea how they should be arranged

[@florincatalinene8320]

Does the objective need to be recalibrated after putting it together again? I am very unsure if I should start to repair mine by myself..

[@CamerasLensesEtc]

If you want to have the best results, then yes, it has to be calibrated, but it is not easy to do that at home, and I doubt that canon service would do that. I would highly recommend to mark and put back the eccentric screws as they were in the lens, that way the lens is closest to the original calibration.

[@drbockel2]

This was a really helpful tutorial. I ended up having to purchase a new aperture for $50, which was not a big deal. Then when repairing, my secondary aperture fell on the ground and of course all of the blades fell out. I managed to put it back together, and then though I followed you instructions perfectly putting the lens back together. However, when I turned on the camera, the lens did not focus (and my focal length didn't go the entire range (more like 30-70). Obviously I made a mistake somewhere, though I don't know exactly where, or why it won't focus. I have completely disassembled the lens once more to try again, but am hoping you might have an idea as to why the focus was not working? Also, what are "eccentric screws" and what does that mean exactly? I thought I marked them well enough but there were several weeks between disassembly and reassembly and it's possible that I didn't get them back in the same exact place. Would that have anything to do with the focus issue? My camera still gave the Err 01 message when I turned it back on. Very frustrating! Any ideas would be greatly appreciated.

[@CamerasLensesEtc]

Focusing problem: most likely the USM motor is not connected to the focusing lens element... if you move the manual focusing ring, is there a lens element moving? (As I remember, a lens element in the back should move.) Zooming problem: Maybe a ring inside the lens is not put back at the correct position. Follow my assembly video exactly, especially when I'm putting back the tubes inside the lens. The eccentric screws are not going to cause focusing or zooming problems. Error 01: check the connectivity of the aperture cable, clean the connector of the cable at the end, check if you can close and open the aperture unit mechanically.

[@drbockel2]

@@CamerasLensesEtc So I went back through, took everything apart and put it back together again as precisely as possible. I now have the zoom and autofocus working...but I'm still getting Error 01 and can't figure out why. The camera/lens seems to be working exactly as it should but I can't shoot with the aperture above 2.8. What else could be going on? Could it be something with the PCB?

[@CamerasLensesEtc]

@@drbockel2 When you disassembled it, have you checked the connections of the cable? Have you changed the cable? The problem could be with the PCB, but in order to test it, you need an another lens.

[@pieciak]

I replaced the tape, after twisting everything, manual focus with the ring and autofocus do not work, at what point did I do something wrong that even manual focus does not work?

[@CamerasLensesEtc]

First, I would make sure that the USM motor is connected to the focusing lens elements group.

[@UpperEgyptRadio]

Good morning sir, i have an issue with my lens canon EF 24-70mm f/2.8 L Focus work fine with me but there's no sharp at all plus colors not looks like reality and i can send you raw samples for more explaining can you tell me what's the problem and how much it coast to solve it

[@CamerasLensesEtc]

Check if the rear lens element is wobbling back and forth 1-2 mm. If yes, then the problem could be that the plastic collars of the screws broke.

[@Miguel-fm8xh]

I completely melted the part of 23:20, is it important? I cut that plastic piece apart and I saw no electrical component in there, what is its use?

[@CamerasLensesEtc]

Yes, it is. It is a sensor for checking if the aperture is completely open. I would recommend to buy a new aperture unit if there is any for sale.

[@esieyleul2397]

Can I send you the same lens with the same problem and can it be repaired?

[@CamerasLensesEtc]

No, I don't do repairs for clients.

[@scott37040]

Symptoms: When I look through the viewfinder, I see "snow" and it's much darker than what I see with the naked eye. Secondly, when I press the shutter button to take the shot, I get an Err 01 message that says "Communications between the camera and lens is faulty. Clean the lens contacts." Everything was fine until my lens tumbled out of the car and hit the pavement! Dry, sunny day. So what's wrong with my lens and can it be fixed?

[@CamerasLensesEtc]

I would check if the aperture is working. Err01 message pops up if the aperture cable is broken, but in your case I think the aperture unit might be damaged due to the fall.

[@Oseiwe]

Lens repair is HARD. Often not worth the effort, unless an expensive lens like this. A $50 lens often has same level of difficulty, which is insane

[@CamerasLensesEtc]

True, that some of the lenses not worth repairing, but I would say that depends on the worth of your freetime.

[@pieciak]

kzbin.info/www/bejne/i4PZYmuOg8uch5Y the second pin fell out and the wire broke off, I made the pin, but where can I fix the wire for this pin? Will it work from any other pin?

[@CamerasLensesEtc]

I wouldn't bother with that, I would just buy a new aperture unit, costs ~45 USD on ebay. It is very hard (if not impossible) to repair it.

[@BOLELEMAXRD12]

subtitle please español

[@CamerasLensesEtc]

Subtitle what I'm saying is not important, you can follow the instructions just looking at the video without sound. If you really want subtitles, you can turn on automatic subs.

[@ketankarelia2203]

skip openning 5: 00 to 6: 10, it whole barrel opens easily..

[@CamerasLensesEtc]

It is safer to remove the zoom ring, because the zoom brush could be damaged.

[@sami..1913]

can you send me a Canon 70d camera and i send you flowers and thank you

[@CamerasLensesEtc]

Thank you for your generous offer, but I pass that.

[@thelittleerik4806]

You forgot to mention that at 24:05 the pins there can easily come out and break. It is fastened in plastic so due to heat they dislodge almost immediately. A head's up or a warning could have been nice. Now i'm sitting here with a bricked lens. Thanks for that.

[@CamerasLensesEtc]

Instead of blaming others for your failures, why don't you go to ebay, and buy an aperture unit with the cable?

[@thelittleerik4806]

@@CamerasLensesEtc those pins are very very prone to break, the pins with a white base, 4 of them on right bottom, which are in 1 row. and nobody was letting me know. That was a very tense moment. I managed to realign the pins and solder them. Both of the videos were informative and helpful. Thank you. The lens works. You did a great job with both of the videos.