Thanks Alwin, so glad it worked for you too. It has indeed brought my lens back to life. In fact it works like a proper lens should. And it's worked perfectly for several years now. Well done you, and wishing you continued success for the future.
You need to open all the lens down to the AF motor unit and take out the USM clutch, lubricate it properly and put back for proper solution. Canon used high viscosity lubricant in the clutch section which is unable to move the focus element without any slipping. That's why they released the 2nd gen of this lens.
Yes, true that. However, this particular lens is very difficult to disassemble down to USM unit.. there are many decentering collars to be removed etc.. thankfully most canon lenses are pretty easy to maintenance.
There is no clutch… 3 rings operate on friction. There is no lubrication. Slipping likely caused by the surface getting worn smooth and lost friction. Over turning focus past limits does that slowly.
@@Guoenyi Correct, this is why Canon will swap the whole USM Ass'y (if the focus barrel system is not impact damaged anyway, totally different case though). If this was just a question of lubrication, Canon service would do just that.
@@The-four-o-five Yeah canon replaced my usm mech and the thing is quite facinating to play with. I thing with careful use it will be good for a very long time.
Thank you Kelcey, I'm so glad it worked for you too. I love how precise the focus is on my lens as I never want an auto focus for video. Thanks again for your lovely comment.
Ooh, that sounds like a job for the professionals! Maybe some internal mechanism has worn-out. They are complicated pieces of equipment, way beyond my help. So sorry, hope it doesn't cost too much to fix. 😧
mine has the same problem - but AF still seems to work, albiet a bit slow. Manual focus is doing exactly what yours is doing, however I never manual focus as a sports shooter so this wasn't a problem for me. Will this also fix the autofocus issues?
Hi Eric please don't try this if the auto focus still works. It's only for people who don't use auto focus (like me) when filming video footage. The extra friction will damage the auto focus motor! As it is trying to also move the focussing ring when the wrist band is fitted.
@YDS Together it depends on if you only want to use it manually or autofocus. Unfortunately you can't have not with this "fix." I only ever use manual focus because I shoot video. But if you only shoot auto focus then this probably isn't for you. Thanks for your feedback, so glad it worked for your lens whether you keep it manual only or remove the band for auto.
Once the lens has been converted, it should NEVER be used in autofocus as it will NOT work and very probably damage the motor / camera or both. This fix is only to transform the lens into a manual one and nothing else. Hope that is clear to anyone attempting this modification.
I was wondering! I have a loose barrel on my lense at the end you just dismantled in your video. Is this how i would fix the problem and just tighten screws. Obviously ignoring the wristband replacement. Thanks
Without seeing the lens it's difficult to say as they are very complicated inside. The focussing barrel doesn't really attach to anything. You can easily take off the collar as I show in the video and the barrel comes off easily. Its worth a try! Good luck... This video may help if its the same type. th-cam.com/video/DpiauO9xeO8/w-d-xo.html
Hey I have a 6d mark 2 and probalem is error code 20 and but shutter is well OK but mirror is not working mirror unit gear is OK what is the problem so please help me comment now
I did a Google search and came up with this. Hope it works for you... A malfunction with the mechanical mechanism has been detected. Resolution: Turn the power off, then remove and re-install the battery. Then turn the power on again. cpn.canon-europe.com/content/education/infobank/camera_settings/eos_error_codes_and_messages.do
Hi Maz I'm not sure about that. If it's the same gubbins inside then probably yes, if the silicone wrist band is the right size. I suspect this lens is much wider so if you can find one that's the right size then give it a go! Please let me know how you get on. Good luck.
Я разобрал чуть дальше..подняв резиновое кольцо и снял металлическое кольцо..освободив доступ кольцам ручного автофокуса...И между колец намотал ниток ,тем самым раздвинув кольца и увеличил плотность прижатия колец...Итог работает ,как от ручной ,так и от автоматической фокусировки
Thank you for your extra information. I'm trying to imagine exactly what you did to the lens. So glad you can use auto and manual doing what you did. If you are able to create a video of your successful experiment, I'm sure people would appreciate your time and effort to help and explain your system. 👍
Hi this lens also has Image Stabilisation. You may have a new version as this lens is a few years old now. There is a separate lens inside that is connected to the IS circuit and this mod is nowhere near this mechanism. So I would assume you are good to go and try it out if your manual focus is faulty. It will impede auto focus 100% so if that is NOT needed then you could go ahead with the mod. You can always reverse the mod if you follow the second part of this video. Good luck and let me know how you get on. Thanks for your comment.
Hi, a few people have said they have a similar problem with the larger f2.8 lens. Unfortunately I haven't had the chance to take one apart to see if the fix would work. If the internal mechanism is of a similar design then in theory it could well work on this lens too. If you try this please let everyone know here the outcome either way. Thank you for your comment, sorry I couldn't help more.
I have an Ef 100 x 400 11 lens and I use it a lot out in the sand/dirt. The focus and zoom are now gritty and crunchy as they move. Is there an easy way to clean that part of the lens or just send it to Canon for repair? Thanks
Hi Tim, thanks for the lengthy video and description. Have you tried this with a 70-200 2.8 IS II? Mine is slipping focus manually and I'd rather take out the front rings than open up the back! If this works I could see doing it when I need the lens for video and just removing the band when i need AF for stills.
Hi Jimmy, I honestly couldn't say if this works for the larger f2.8 lens. I would imagine that the mechanics are similar but I have no idea. If you do attempt this maybe you could return and leave your feedback results as I and possible others in the future would like to know. Best of luck if you do try this fix. Cheers...
Tim Hollingworth We originally tried your technique but we struggled to open the top unit with wooden skewers. Just bought some specialised metal prongs online, wish us luck!
Christopher Thomson Hi Chris glad your having a go with fixing your lens with my instructions. Yes it is a good idea to have the proper tools to minimise damage. Good luck and please let us know how you get on. 👍
I gona try! Thank you for the advice! I have see a 45min video with full dismount for the same problem, if i can repair like this video you going to save my life! (and wallet) sry for my english!
I honestly have no idea what grease they use to create the required friction but clearly it stopped working on many lenses. Hope you can sort it out without it costing too much money.
Ooh 😯 that's a tricky one! I have no experience of sourcing tiny screws, but they must exist somewhere. Maybe eBay is the place to search first? Good luck, please let us know how you get on.
I have the same issue. I need AF so I send it to Canon for repair. It costs me $400 Canadian dollars to fix it. They replaced the decentering collar and USM focusing assembly.
@@TimHollingworth Welcome. With the numbers of issues out there, it should be a recall or at least free repair. I guess Version 2 is out already...hopefully they have that sorted out this time.
@@ericthestone Yes I agree but it would cost them £/$1000's to put right the fault. It's a great lens and I use it all the time on my video work. It's even better to focus after the "fix" as I have no real need for auto focus. (Except for stills which isn't very often.) I would be nervous about getting the version 2 though!
Hi the short answer is any will work. Because the Canon 80D has the smaller crop censor it will increase the zoom of any lens. Take the focal length of your lens x 1.6 equals the equivalent focal length, when you use it on your crop sensor camera. For example the 200mm lens on a crop sensor camera will have the equivalent of: 200mm x 1.6 = 320mm and the 300mm x 1.6 = 480mm. It all depends on how close you want see things.
SUPERRRRR!!!!! it realy does work!!!!!!!! Thank you so much!!!!!!!!!!!! ...So now my lens became manual as it was told in video... but it is better than payng 150$...
Hi David, yes I was surprised how well it works too. So glad you tried it and commented on your results. I like the way you can twist the focus ring into a more solid place and have a fast pull focus and then twist the focus ring back until its smooth and have the geared precision focussing back. Thanks again, I hope this gives more photographers the courage to fix their own lens. Tim
94 7.3 IDI turbo Diesel - Hi it's a simple process to get it working again manually but please remember it will stop any auto focus from working and potentially damage the motor if you do try to use it in auto. My lens is only used in manual focus and it works beautifully. Good luck and let me know how you get on.
Mr. Farkas Hi thanks for trying this. Maybe the wristband is too big or small in diameter or thickness? Or maybe it's pushed down too far or not enough? All I can say is that it does genuinely work. So please persevere as it is worth it in the end. Do let me know when you get it working. Thanks again for trying.
Lakukan pembersihan dan pelumasan pada slongsong lensa. Buka dari penutup atas. Saya mengalami hal yang sama, tetapi puji tuhan sudah teratasi dengab cara tersebut. Masalahnya ada pada slongsong yang seret.
Hi Isaac I'm sorry to hear that you damaged the screws. I honestly have no idea where you could get replacement screws. Firstly you would need to know the type of thread and sizes. Perhaps eBay would be my first port of call once you have determined the dimensions. I'll try a search and see what I can find for you. I'll post again here if I come up with the goods. Thanks for your comment.
it didn't work in my case, I mean it worked for maybe 10 minutes and than slipped behind the assembly. had to remove it and sent to Canon for repair. But good point anyway!
Hi that is a pity, maybe it wasn't the right size. I've had mine working perfectly for over 2 years now. The only slight issue I have ever had was once when I was filming outside on a really cold day. I twisted the focus the opposite way until it worked again. I'm so sorry it didn't work for you. By the way how much did it cost for canon to fix it, please? Thanks for your comment.
I'm not sure if my fix would work on yours as I don't have that one in my kit. If the front lens extends out when you zoom, I don't think it would. It sounds like an expensive repair. Good luck :-/
Hi Hao, thank you for trying my fix. Yes as I said in the video at 8:13, this WILL happen if you do the modification. The tiny Auto Focus motor is trying to turn ALL the focussing ring and the extra drag stalls the motor which will burn out if you continue. If you want to restore Auto Focus see the second half of the video to remove the wristband at 11:05 and you will have auto focus again. Please let me know if the fix worked ok for you when using the lens in manual an then restoring AF. Thank you for your reply.
Yes it's not cheap for a professional repair to get the lens back to 100% as it should be. Mine is only a half way fix to turn it into a manual only lens. It's still working perfectly and it feels good in your hand to connect directly to the lens. Rather than a sloppy adjustment. In reality this lens is meant for autofocus only, but I much prefer it in manual for my video work. Thanks for the information and do let us know if you attempt to fix it yourself.
Привет, Илья Ткачев, похоже, что у вас снова работает объектив. Отлично сработано. Hi Ilya Tkachev looks like you got your lens working again. Well done.
Telling people to use a Phillips screwdriver on the JIS screws in Japanese lenses like this is about the worst advice you can give them and will lead to even higher costs when they have to pay the shop extra $$$ to drill the stripped screw heads out on top of the needed repair. To anyone attempting this mod: first Google "JIS screwdriver" and save yourself a lot of heartache.
bgohacki Thank you for your valuable information. I for one had no idea there was a different type to the Phillips. QUOTE: JIS - Japanese Industrial Standard. ... JIS looks much like a Phillips screw (and even more similar to Frearson), but is designed not to cam out and will, therefore, be damaged by a Phillips screwdriver if it is too tight. Heads are usually identifiable by a single raised dot to one side of the cross slot.
It stopped working as a manual lens a couple of years ago. I added a silicone band and I could use it again, perfectly. I never used it on autofocus. To me it is a 100% fix. Maybe a more accurate term would be bodge?
It worked perfectly. thanks sir.
Thanks Alwin, so glad it worked for you too. It has indeed brought my lens back to life. In fact it works like a proper lens should. And it's worked perfectly for several years now. Well done you, and wishing you continued success for the future.
You need to open all the lens down to the AF motor unit and take out the USM clutch, lubricate it properly and put back for proper solution. Canon used high viscosity lubricant in the clutch section which is unable to move the focus element without any slipping. That's why they released the 2nd gen of this lens.
Yes, true that. However, this particular lens is very difficult to disassemble down to USM unit.. there are many decentering collars to be removed etc.. thankfully most canon lenses are pretty easy to maintenance.
There is no clutch… 3 rings operate on friction. There is no lubrication. Slipping likely caused by the surface getting worn smooth and lost friction. Over turning focus past limits does that slowly.
@@Guoenyi Correct, this is why Canon will swap the whole USM Ass'y (if the focus barrel system is not impact damaged anyway, totally different case though). If this was just a question of lubrication, Canon service would do just that.
@@The-four-o-five Yeah canon replaced my usm mech and the thing is quite facinating to play with. I thing with careful use it will be good for a very long time.
This fixed my lens that was knocked off a table, wouldn't auto or manual focus. Now I can Manual focus again with it! Amazing, saved me $600+
Thank you Kelcey, I'm so glad it worked for you too. I love how precise the focus is on my lens as I never want an auto focus for video. Thanks again for your lovely comment.
Hi, do you have any clue how to fix a sigma 35 mm 1.4 lens my manual focus ring is not moving past a certain point.
Ooh, that sounds like a job for the professionals! Maybe some internal mechanism has worn-out. They are complicated pieces of equipment, way beyond my help. So sorry, hope it doesn't cost too much to fix. 😧
I got it fixed I sent it into Sigma and it cost 300 not too bad since I only bought it for 160 @@TimHollingworth
where to buy the wrist band? I couldnt find one without logo or wrtiting
Don't worry about the writing, it should work ok as long as it's about the right size. Thanks for you comment. Do let us know when you get it working.
mine has the same problem - but AF still seems to work, albiet a bit slow. Manual focus is doing exactly what yours is doing, however I never manual focus as a sports shooter so this wasn't a problem for me. Will this also fix the autofocus issues?
Hi Eric please don't try this if the auto focus still works. It's only for people who don't use auto focus (like me) when filming video footage. The extra friction will damage the auto focus motor! As it is trying to also move the focussing ring when the wrist band is fitted.
@YDS Together it depends on if you only want to use it manually or autofocus. Unfortunately you can't have not with this "fix." I only ever use manual focus because I shoot video. But if you only shoot auto focus then this probably isn't for you. Thanks for your feedback, so glad it worked for your lens whether you keep it manual only or remove the band for auto.
@Nausea You basically have to. Otherwise you will kill/burn out the USM motor and maybe even more electronic wise.
How is the auto focus? isn't it by adding rubber, in auto focus mode the motor work becomes heavy?
Once the lens has been converted, it should NEVER be used in autofocus as it will NOT work and very probably damage the motor / camera or both. This fix is only to transform the lens into a manual one and nothing else. Hope that is clear to anyone attempting this modification.
I was wondering! I have a loose barrel on my lense at the end you just dismantled in your video. Is this how i would fix the problem and just tighten screws. Obviously ignoring the wristband replacement.
Thanks
Without seeing the lens it's difficult to say as they are very complicated inside. The focussing barrel doesn't really attach to anything. You can easily take off the collar as I show in the video and the barrel comes off easily. Its worth a try! Good luck... This video may help if its the same type. th-cam.com/video/DpiauO9xeO8/w-d-xo.html
Hey I have a 6d mark 2 and probalem is error code 20 and but shutter is well OK but mirror is not working mirror unit gear is OK what is the problem so please help me comment now
I did a Google search and came up with this. Hope it works for you...
A malfunction with the mechanical mechanism has been detected. Resolution: Turn the power off, then remove and re-install the battery. Then turn the power on again.
cpn.canon-europe.com/content/education/infobank/camera_settings/eos_error_codes_and_messages.do
Would this fix work/be the same as on a 100-400 is lens please?
Hi Maz I'm not sure about that. If it's the same gubbins inside then probably yes, if the silicone wrist band is the right size. I suspect this lens is much wider so if you can find one that's the right size then give it a go! Please let me know how you get on. Good luck.
Hi, can this work for an 85mm Lens? The focus ring won’t move at all?
That sounds pretty bad. I wouldn't think this fix would help your lens. Maybe a job for Canon :(
Я разобрал чуть дальше..подняв резиновое кольцо и снял металлическое кольцо..освободив доступ кольцам ручного автофокуса...И между колец намотал ниток ,тем самым
раздвинув кольца и увеличил плотность прижатия колец...Итог работает ,как от ручной ,так и от автоматической фокусировки
Thank you for your extra information. I'm trying to imagine exactly what you did to the lens. So glad you can use auto and manual doing what you did. If you are able to create a video of your successful experiment, I'm sure people would appreciate your time and effort to help and explain your system. 👍
Hi. Got the same lens but with IS. Do you think this mod could affect image stabilisation system?
Hi this lens also has Image Stabilisation. You may have a new version as this lens is a few years old now. There is a separate lens inside that is connected to the IS circuit and this mod is nowhere near this mechanism. So I would assume you are good to go and try it out if your manual focus is faulty. It will impede auto focus 100% so if that is NOT needed then you could go ahead with the mod. You can always reverse the mod if you follow the second part of this video. Good luck and let me know how you get on. Thanks for your comment.
Tim Hollingworth Thank you for your reply, I will let you know when I will do the mod!
Mr Tim i need your help, I have 70-200 2.8 ii usm , the manual ring won’t turn... please help me
Hi, a few people have said they have a similar problem with the larger f2.8 lens. Unfortunately I haven't had the chance to take one apart to see if the fix would work. If the internal mechanism is of a similar design then in theory it could well work on this lens too. If you try this please let everyone know here the outcome either way. Thank you for your comment, sorry I couldn't help more.
I have an Ef 100 x 400 11 lens and I use it a lot out in the sand/dirt. The focus and zoom are now gritty and crunchy as they move. Is there an easy way to clean that part of the lens or just send it to Canon for repair? Thanks
I would suggest you send it in for professional repair and cleaning. It's not easy taking lenses apart to that depth.
Hi Tim, thanks for the lengthy video and description. Have you tried this with a 70-200 2.8 IS II? Mine is slipping focus manually and I'd rather take out the front rings than open up the back! If this works I could see doing it when I need the lens for video and just removing the band when i need AF for stills.
Hi Jimmy, I honestly couldn't say if this works for the larger f2.8 lens. I would imagine that the mechanics are similar but I have no idea. If you do attempt this maybe you could return and leave your feedback results as I and possible others in the future would like to know. Best of luck if you do try this fix. Cheers...
Have the exact same problem but with my 70-200 2.8 - Do you think it could work for me?
I can't honestly say as I have not tried it on that lens. But if you do attmpt it please let us know if it works or not.
Tim Hollingworth We originally tried your technique but we struggled to open the top unit with wooden skewers. Just bought some specialised metal prongs online, wish us luck!
Christopher Thomson Hi Chris glad your having a go with fixing your lens with my instructions. Yes it is a good idea to have the proper tools to minimise damage. Good luck and please let us know how you get on. 👍
I gona try! Thank you for the advice! I have see a 45min video with full dismount for the same problem, if i can repair like this video you going to save my life! (and wallet) sry for my english!
Hi were you successful with fixing your lens?
Please tell us what grease to use when repairing this lens
I honestly have no idea what grease they use to create the required friction but clearly it stopped working on many lenses. Hope you can sort it out without it costing too much money.
Accidentally lost a screw. Where could I buy new screws?
Ooh 😯 that's a tricky one! I have no experience of sourcing tiny screws, but they must exist somewhere. Maybe eBay is the place to search first? Good luck, please let us know how you get on.
I have the same issue. I need AF so I send it to Canon for repair. It costs me $400 Canadian dollars to fix it. They replaced the decentering collar and USM focusing assembly.
ericthestone Hi thanks for letting us know the cost of repairing your lens. It does seem to be a very common fault. Thanks again.
@@TimHollingworth Welcome. With the numbers of issues out there, it should be a recall or at least free repair. I guess Version 2 is out already...hopefully they have that sorted out this time.
@@ericthestone Yes I agree but it would cost them £/$1000's to put right the fault. It's a great lens and I use it all the time on my video work. It's even better to focus after the "fix" as I have no real need for auto focus. (Except for stills which isn't very often.) I would be nervous about getting the version 2 though!
Canon EF-S 55-250mm f/4-5.6 IS STM or EF 70-200mm f/4L USM or Canon EF 70-300mm f/4-5.6 IS USM which is good for canon 80 D ?
Hi the short answer is any will work. Because the Canon 80D has the smaller crop censor it will increase the zoom of any lens. Take the focal length of your lens x 1.6 equals the equivalent focal length, when you use it on your crop sensor camera. For example the 200mm lens on a crop sensor camera will have the equivalent of: 200mm x 1.6 = 320mm and the 300mm x 1.6 = 480mm. It all depends on how close you want see things.
SUPERRRRR!!!!!
it realy does work!!!!!!!!
Thank you so much!!!!!!!!!!!!
...So now my lens became manual as it was told in video...
but it is better than payng 150$...
Hi David, yes I was surprised how well it works too. So glad you tried it and commented on your results. I like the way you can twist the focus ring into a more solid place and have a fast pull focus and then twist the focus ring back until its smooth and have the geared precision focussing back. Thanks again, I hope this gives more photographers the courage to fix their own lens. Tim
Thank you again! You Realy helped ;)
I have the same exact problem except it has that problem when pointing upward.
94 7.3 IDI turbo Diesel - Hi it's a simple process to get it working again manually but please remember it will stop any auto focus from working and potentially damage the motor if you do try to use it in auto. My lens is only used in manual focus and it works beautifully. Good luck and let me know how you get on.
I did this step-for-step but I can't seem to get my focus ring to work again.
Mr. Farkas Hi thanks for trying this. Maybe the wristband is too big or small in diameter or thickness? Or maybe it's pushed down too far or not enough? All I can say is that it does genuinely work. So please persevere as it is worth it in the end. Do let me know when you get it working. Thanks again for trying.
Lakukan pembersihan dan pelumasan pada slongsong lensa. Buka dari penutup atas. Saya mengalami hal yang sama, tetapi puji tuhan sudah teratasi dengab cara tersebut.
Masalahnya ada pada slongsong yang seret.
Senang Anda membuatnya bekerja. Terima kasih atas komentarmu.
I ruined the screw head where to buy them?
Hi Isaac I'm sorry to hear that you damaged the screws. I honestly have no idea where you could get replacement screws. Firstly you would need to know the type of thread and sizes. Perhaps eBay would be my first port of call once you have determined the dimensions. I'll try a search and see what I can find for you. I'll post again here if I come up with the goods. Thanks for your comment.
didn't unfortuately not work with mine... (crash damage but same failure)
Sorry it didn't work out for you. Many thanks for trying and letting me know.
it didn't work in my case, I mean it worked for maybe 10 minutes and than slipped behind the assembly. had to remove it and sent to Canon for repair. But good point anyway!
Hi that is a pity, maybe it wasn't the right size. I've had mine working perfectly for over 2 years now. The only slight issue I have ever had was once when I was filming outside on a really cold day. I twisted the focus the opposite way until it worked again. I'm so sorry it didn't work for you. By the way how much did it cost for canon to fix it, please? Thanks for your comment.
guess I could keep my hopes on my 55mm lens accidentally dropped, now auto focus works but manual ring keeps turning just like yours. :-S
I'm not sure if my fix would work on yours as I don't have that one in my kit. If the front lens extends out when you zoom, I don't think it would. It sounds like an expensive repair. Good luck :-/
Just tried this, and it didn't work
So, I do this , I lost AF?
Hi Hao, thank you for trying my fix. Yes as I said in the video at 8:13, this WILL happen if you do the modification. The tiny Auto Focus motor is trying to turn ALL the focussing ring and the extra drag stalls the motor which will burn out if you continue. If you want to restore Auto Focus see the second half of the video to remove the wristband at 11:05 and you will have auto focus again. Please let me know if the fix worked ok for you when using the lens in manual an then restoring AF. Thank you for your reply.
Tim Hollingworth thanks for the explanation, anyway, seems like send back canon can fix the issue . Anyway thanks for your video.
Thanks for your reply, Iwould be interested to hear how much Canon charges for this repair. Good luck.
Tim Hollingworth I can expect some wallet shaking. Fortunately currently my AF is still good.
I went to a canon shop and they quoted me 3 figures for that
Yes it's not cheap for a professional repair to get the lens back to 100% as it should be. Mine is only a half way fix to turn it into a manual only lens. It's still working perfectly and it feels good in your hand to connect directly to the lens. Rather than a sloppy adjustment. In reality this lens is meant for autofocus only, but I much prefer it in manual for my video work.
Thanks for the information and do let us know if you attempt to fix it yourself.
👍🤝
Привет, Илья Ткачев, похоже, что у вас снова работает объектив. Отлично сработано.
Hi Ilya Tkachev looks like you got your lens working again. Well done.
Jesus how you going to play with it! Get on with it already
Ha-ha its called build up! Hope you found it useful when I did eventually got on with it :)
@@TimHollingworth Umm no I stopped watching.
Telling people to use a Phillips screwdriver on the JIS screws in Japanese lenses like this is about the worst advice you can give them and will lead to even higher costs when they have to pay the shop extra $$$ to drill the stripped screw heads out on top of the needed repair.
To anyone attempting this mod: first Google "JIS screwdriver" and save yourself a lot of heartache.
bgohacki Thank you for your valuable information. I for one had no idea there was a different type to the Phillips. QUOTE: JIS - Japanese Industrial Standard. ... JIS looks much like a Phillips screw (and even more similar to Frearson), but is designed not to cam out and will, therefore, be damaged by a Phillips screwdriver if it is too tight. Heads are usually identifiable by a single raised dot to one side of the cross slot.
"Fix" is an exaggeration
It stopped working as a manual lens a couple of years ago. I added a silicone band and I could use it again, perfectly. I never used it on autofocus. To me it is a 100% fix. Maybe a more accurate term would be bodge?