Repair: Sigma 10-20 EX DC HMS EOS Autofocus Fix

Dissembling the lens to look into the issue with autofocus of Sigma 10-20mm f4-5.6 EX DC HSM.
Lengthy video but successful repair. Can be useful for people who interested in lens repairs.

[@hansa3580]

Just watched this video for the 4th time! Thanks to your post, I am able to get my Sigma EX 85mm/1.4 90% operational! Just picked it up at a local pawn shop, "as-is", wasn't autofocusing, wouldn't engage in manual focus. Turns out, lens must have been impacted, may be bumped from the front, probably on the body. Was worth the risk to buy it as-is; following your procedure, loosed up the lens focus "rollers", able to focus from 2.8' to about 40-50', but, getting clear images!! Great post!!!!!!!!!!!!! Very encouraged now!

[@ulflulfl9464]

Thanks for this video! Encourages me to open mine, as it does not autofocus exactly at 10 mm intermittently. If setting a little bit above 10 mm AF works fine all the time --- annoying. As the lens is my "work horse" on motorcycle trips for many years, loose screws might very well be the reason. BTW: No need to appologize for the lengthy video, I take all the details I can get ;-)

[@atse51]

Thanx for your video. I had the same problem and with a help from you I solved the problem. I just test the lens and the auto focus works perfect.

[@carlosrios987]

I have the same lens but it is for the Nikon brand, I mount it on my D610 and it recognizes the lens but when I switch it to AF the autofocus does not work, it only works in Manual. One question, it doesn't matter if it's FX, right? I wait your answer.

[@pavelantoniadi8339]

Good work, man!

[@matiaslanyi236]

Hi, I have a problem with a Sigme focusses, de ultrasonic motor is noisy and work it suck. Can you tell me, how it works, and is it posible respir it? Thanks

[@TRolla82]

Having issues with my 15mm fish eye going to see if this is the same issue fingers crossed 🤞

[@sujeeshntnadackalthomas8197]

My wide angle lens(Sigma 10-20) always shows aperture zero. Can anyone suggest me why this like this? Is it a problem with my lens or something else?

[@hansa3580]

Will do some fine tuning; thanks again!!!

[@Bryantfstephens]

I’m thinking about doing this for my sigma 170-500mm f/5-6.3 apo dg as it doesn’t tack focus. Just a little off but it is off. Micro adjust doesn’t seem to help as it is always wrong even with the adjustment. Is the problem slight mid focus or is it something different?

[@TheEmulsufiedEye]

Hi, I bought a second hand sigma 10-20 3.5 for Nikon, I have a D7100. Autofocus doesn’t work - all my other lenses do. I can hear a clicking sound when it’s trying to focus, is this the same issue?

[@MrXDF]

Hey,

[@brianliou8877]

Hi, Amirnasher. Thanks for this great video. I have a Sigma 28-70mm Aspherical EX lens for Canon 5D classic. The autofocus seems doesn't work. When I turn the focus ring, there is grinding, scratching sound from it. When I half press shutter bottom to focus, there is motor sound but no autofocus engaging. Is this the same problem? Thanks.

[@Zwalter]

Does this work on sigma 150-500mm f/5-6.3 AF APO DG OS HSM??? I have the similar issue but the autofocus motor just doesn't work. Doesn't even make a sound.

[@ginoginetti]

hi. How can i see if the motor is broken? My af doesn't work anymore. Do i need an electronic tester?

[@nevermindidontknow]

Hello, I bought Sigma 10-20 and autofocus is not working with Nikon d3500. If it common problem? Incompatible with that model? Or can be fixed ?

[@MrDouglasEdson]

How to open the front element of the sigma 10-20?

[@VitoPastore]

Hi! I have an issue but it is not with autofcus, well in fact it is not an issue until now but is anoying. I have the sigma 10 20 for almost 5 years without any problem, it accidentaly dropped (of course) a couple of days after buying it, but the only thing that broke (it bend) was the filter. But today I took it and I heard an extrange noise when I moved it, like a little loose plastic piece tha move from one place to another I cant say where, if it is from side to side or from front to back in the lens barrel. I tested it in different focal lenghts and diaphragms and everything seems to be fine: autofocus, image (so it seems that is no broken glass, I think...), etc. I dont know what can it be. What do you think knowing that you opened it? thanks in advance

[@vloguy]

Hi, sir, i bought Sigma 150mm 2.8 macro lens, 2nd hand and it arrived well packed all metel build, little scratch no wear and tear...but when i attached it to my nikon d600, i does not work, no Af or MF , just gives little scratching sound from inside the lens when u click on shutter for AF but focal length indicator does not change....any guss.. Would be much appreciated...thank u in advance.....

[@kirkkirkkirk_audiovisualre2492]

Mine has a crack underneath. Can it be repaired?