Reparing autofocus on the Canon kit lens - Page 1
Forum section: electronics / repair

author: Peabody
author_rank: Super Contributor
timestamp: September 25, 2023, 04:05:25 pm
content: That would be the Canon EF-S 18-55mm IS as found on older Canon Rebel DSLRs such as my 550D T2i.The autofocus no longer works on this lens. Well, it works in one direction, but not the other. So if focus is manually adjusted so the lens is fully extended (i.e. for close up focus), then autofocus will retract it back to the correct position for distant focus. But if it starts fully retracted, autofocus will not extend it at all from that position. I don't detect any gear issues.From what I gather online, this is a common problem, which is usually caused by a break in a trace found on the autofocus flex cable. I found a video showing how to replace that cable, and have ordered a replacement on eBay. It appears to be challenging, but not impossible. This is a $100 lens, so sending it in to Canon for repair is not going to make economic sense if they would even do it at all, which I doubt.I just wondered if anyone here has done this repair, and if so, do you have any suggestions or warnings? I know I need to avoid getting dust in the lens to the extent I can, but there's no way to prevent that completely.Well I figure this is worth a try. The replacement cable was only $10 (actually, I get 10 of them for that price). I have a 50mm 1.8 lens that still works fine, and I doubt I will replace the kit lens if it can't be repaired, so I might as well give it a shot. Anyway, here's the video I found:

author: Spuddevans
author_rank: Unknown
timestamp: September 25, 2023, 06:15:11 pm
content: I haven't repaired that specific lens, but I had a similar issue with the EFS17-85 lens, which needed a flex ribbon replacing (as it turned out, the replacement only lasted a few months use before it also failed, but maybe I got a dud?)What I did to give myself the best chance of not losing any bits and also getting it back together, was to get a bunch of parts bags and number them all from 1 to whatever.I also had a guide of the repair from the internet which I followed.Then for each stage of disassembly, the screws and parts would go into their own labelled bag in sequence and I would also take a photo on my phone of the "stage" before disassembly of that stage. I think I ended up with about 19 bags with parts/screws in, but because they were all numbered and filled in sequence, re-assembly was made much more straightforward as it was simply a case of working backwards down the numbered bags.Take your time, take plenty of notes/photos of each stage, or maybe even set up a video camera to be able to capture exactly how each part comes apart (some bits of my lens had to come out & be replaced in a very specific rotation/angle, if you got it wrong the next stage would not fit back in place!!)Hope you have success with your repair, like I said with my attempt it worked ok for a few months and then failed again with the exact same fault. So I took this as a sign that I should upgrade, so I got a Sigma 17-55mm f2.8 OS lens (I would've loved to get the Canon 17-55mm f2.8is but it was just too much $$$, I rented the canon one for a friend's wedding and was blown away by the sharpness and colour rendition. The Sigma is also very good, but not quite as good as the Canon)Tim

author: Peabody
author_rank: Super Contributor
timestamp: September 26, 2023, 01:59:06 pm
content: Thanks @Spuddevans. The replacement flex cable arrived in the mail, and I was able to do the repair successfully. It took me about an hour, and the hardest part was orienting the new cable correctly. It has adhesive on the back, and I ruined the first one trying to reposition it. So it's good I had multiple replacements to work with. But everything worked on the second try. So this repair is definitely feasible. Apparently this is a very common problem. My flex cable was completely severed, which I think just happens with use and age. I'm not sure it matters, but it looks like the lens should be stored in the 55mm position, which straightens out the flex cable.

author: steve30
author_rank: Frequent Contributor
timestamp: September 26, 2023, 05:06:52 pm
content: I'm glad the repair worked. I had to repair a 50mm f/1.8 a few years ago (an internal plastic clip broke and the whole thing fell apart). On these cheaper ones, it is well worth trying to repair them yourself as they are not worth much, and by the time they break, you have probably had your money's worth anyway.I also own the 18-55mm EF-S, but I have barely used it in years as I tend to prefer primes. I'll bare this topic in mind though in case mine ever gives up.