Disassemble Assemble Canon 75-300mm lens. Fix the stuck Zoom ring

[@fsong00]

Someone asked me to fix his 75-300mm. It ended up I used mine to fix his. So I have my 75-300mm lens as parts. Just reply this thread, I will mail my broken 75-300mm to you at no cost. Only in North America. First come first service!

[@nicholaswentorf3271]

Are you still looking to get rid of the parts lens?

[@fsong00]

@@anands3362 Did you disassemble the lens? You need to open it to see what is exactly the problem. If as you described, you hear the string tension sound, it could be the metal brush. Check my video starting at 10:00 minutes.

[@lumine7653]

Hi! I need help. :( After disaassembling the lens and putting it back, the af ring is loose and can be pulled out from the lens. There also seems to be a gap betwwen the af ring and the zoom barrel.

[@fsong00]

@@lumine7653 you need to carefully rotate the barrel in order to find a path to get the right position in. There is path, just keep rotating. Hope this helps!

[@Snow-wq6ep]

@@fsong00 I've tried rotating the auto focus ring multiple times and It still always have a spot when focusing that the ring just comes out, can you make a video about this?

[@SuzukaSpec]

Thanks for doing this. Don't listen to that guy on the canon forum who said "just get a 70-300 USM II, its a budget zoom anyway" like we all have money to toss around. What a dickhead. I just picked one of these up for 100$ (canadian) used and the zoom ring is a little bit sticky (not completely stuck like yours) and I thought I'd google to see if its a common thing, your video came up straight away. As someone who is very comfortable with disassembling and repairing these types of things, this video is exactly what I needed.

[@fsong00]

Thank you for your comment!

[@Ildskalli]

Thanks a lot for the video, it was very useful. If you're still making these, can you please edit them a bit slower? And also show some of the trickier parts a bit more. The clamps for the flex cables are of a type I hadn't encountered before, and seeing how to put them back in would've been great. Same goes for the zoom ring key, not something I had to reassemble before. Anyway, I did some maintenance on an old and battered 75-300mm III non-USM (it's almost the same lens, only thing that changes is the AF motor) and I messed up and tore the flex that connects the focus and zoom position encoders. Guess what? It still works, both on DSLR and mirrorless, and it's *sharper* now 🤯 (not because of the torn flex, of course, but just thanks to the general cleanup it got).

[@fsong00]

@Ildskalli So glad to hear your successful DIY story!

[@cugreen4439]

Thank you, bro. I did it but failed on a bad screw finally. I will try it soon with another new tool to open the bad screw.

[@herbys68]

Thank you for the video, it was extremely helpful. But after assembling the lens back, my zoom ring no longer works, i can turn the ring and the lens doesn't zoom in or out. I see that there is a metal L-shaped lever at the bottom of the lens that rotates with the zoom cylinder, and my suspicion is that this L is not being grabbed by the zoom ring as it turns. Am I missing a piece there? How does the zoom ring connect to the zoom lever?

[@fsong00]

it must be an assembly issue. The L level should be embedded into the slot of the zoom ring. this way they connect.

[@herbys68]

@fsong00 Ah, got it, it's working now, thanks!

[@herbys68]

Thank you for the thorough and insightful guide, it help me fix my 75-300 lens successfully and save a bundle! Please do other videos like this, I like the way you explain things as you work through the process. Question for you: do you have any idea what kind of grease do these lenses use on the inside? I noticed a tiny amount of grease between some of the rings and barrels, but I had to remove it because it had been contaminated with tiny amounts of sand (fortunately I was able to remove it before it caused scratches and wear). I could try lithium grease, but don't really know if that's the right type. Thanks!

[@jonathaneleyet2702]

Thank you! This was super helpful.

[@brianlai4387]

Instead of drilling another two holes to secure the sides with screws, you could have used Loctite threadlocker on the existing screws that would have hold up with less effort. I'm thinking about getting this lens but by the looks of it I won't be paying more than 60$ for a used one or $45 for a unit affected with fungus given the effort it takes for me to open it up and clean/service the entire unit.

[@fsong00]

@@brianlai4387 Thank you for your suggestion!

[@jackmasham5990]

Thanks for showing how to remove the back. I have this lens that has mould on the elements. How did you take the front element off?

[@fsong00]

Hi, Jack, Starting from 9:50 of this video, it talks about re-installation of the front barrel. Just for your reference: 1. You dont have to remove the front lens glass unit. If you want to do a service cleaning of the glass, you can remove the 3 crews pins. I think they are just pins; 2. remove the Lens ID ring (with the EF 75-300mm marking on it). It was glued to the barrel; 3. The front element barrel is sliding/guiding by the tracks. You need to keep rotating the zoom ring in order to find a place to gently pull it out. Keep experimenting you will find that exit point from the tracks. Hope this helps and let me know. Fan

[@oeksnadr]

Hi, I see it is old video, but in a chanse - I have almost the same problem with my canon ef 70-300 is usm. After disassamble it found bended the part you fixed with 2 screws, it was so badly bended that blocked autofocus + the same way bended and twisted brush. would be awsome to contact you to discuss it and who knows - probably can be fixed!?

[@fsong00]

Then you have to straighten that parts. Just use small hammer to hammer it straight.

[@mickyovts3872]

Dude sorry i know the video is old but how does that rear lens come out ?? Unscrew? Pull up?? Just bought q used one and saw it has a fingerprint inside, but kinda scared to take it apart and clean it....good job on fixing it too

[@fsong00]

I remembered that you just keep twisting, at certain angle it will come out.

[@Jagracoki]

This would have saved my lens, but I broke one of the ribbon cable gate clamps. Anyone know where I can buy a replacement? Thanks. Great video!

[@fsong00]

Have you try ebay? I know the cable can be found easily on ebay.

[@Jagracoki]

@@fsong00 Can you tell me the actual name of the part? I tried several web searches with no luck.

[@Jagracoki]

I found a parts list and diagram here: learncamerarepair.com/downloads/pdf/Canon-EF-75-300mm-f4-56-III-USM-Parts.pdf

[@micksolomano5836]

Well done that's great work

[@fsong00]

Thank you for your comment!

[@SuperJimmyBennett]

drill/tool model please? thanks i could always use a precise drill for small things such as this

[@fsong00]

The precision drill is Dremel. It was almost 20 years. The model no longer exists. Dremel is a high-end tool. They have the latest model. But I don't think a brand name has anything different. There are a lot of cheap precision drills on the market. It is just a small size drill-that is. Hope this helps.

[@jonard7905]

Mine just got stuck today :( Does they have all the same problem? Because I’m not sure I can do the drill part... (I use Tamron 70-300) Thank you in advance!

[@fsong00]

Is your Tamron the VC or non VC version?

[@jonard7905]

Fan Song Photography non VC

[@fsong00]

@@jonard7905 I did search on the Internet, and I don't see people has similar instruction or video on how to fix this problem. Different manufacture has a different design so I am not sure Tamron uses the same Zoom technique as Canon. But if you are going to throw away this lens, I can help you to take a look and see if can fix it. Or you can just simply try it out yourself.

[@kaihughes1857]

What if it's the lens that is throwing a error 99 code? I did all other tests such as removing battery etc and nothing. Tried a different lens and camera is fine but I want to use the 300mm which is throwing the code?

[@innewulan5696]

How about type hj22e 7.6B irse do you have case ring zoom stuck nof full

[@amritpachhai1491]

Thanku sir I may ticnition.

[@OleAJohansen]

Thank you for Very good information. By the way do you know where I can buy Electric Brush The one with 3 small brushes,

[@fsong00]

Hi, Thank you for your comment. As I mentioned in the following post, if you are in North America, I can ship mine to you at no cost. Checked below pinned post.

[@OleAJohansen]

@@fsong00 Thank you. I would but live i Norway so the freight cost will be a lot more thsn I can ask you to pay.

[@duniaseni8823]

Bro, do you sell pin 3 feet for the 75-300 canon lens??

[@Sapper094]

But how did you fix the squeaking sound? You just say you decided to fix the squeaky sound, but you didn’t show what you did? Mine makes this same sound in Autofocus, but it’s fine in manual mode? Thanks

[@fsong00]

The squeaking sound was because of the brush, when I install mine back, the brush was not in the right place right angle, when twist the lens, it causing the sound. Hope this helps!

[@Sapper094]

@@fsong00 many thanks. Would l need to do a complete strip down to get to that part?😊

[@fsong00]

@@Sapper094 if the squeak sound does come from that part and causes focus issue, yes, you have to come a long way to do that

[@Sapper094]

@@fsong00 thanks : ) sounds a little too much for my technical skills lol

[@percymuthivhi8622]

mine hv the same prblm but i dnt hv drill..is there any method i can use to fix it??

[@fsong00]

The idea is to have something that can fix the part to the base. You need to use other method, consider it is a very tight and small space.

[@roguestarr4382]

where can i find the replacement brush?

[@fsong00]

The replacement brush can be found on eBay. Also I collected a lot of broken lens to diy fix since it is a hobby for me.

[@roguestarr4382]

@@fsong00 thanks for the vid. I was able to fix my Len. I bought it for $25. It worked but the focus was messed up and it sounded like a zipper when it adjusted. The little brush from the vid is messed up on mine to but i bent into shape some but i can use a new one. The only other problem is that the zoom feels stiff now. Im not sure what's causing that.

[@RealBesty]

Hi. I have one of these that will now only focus one way - outwards but not back inwards. What do you think might need fixing? :) (Manually it’s fine - no physical sticking)

[@fsong00]

If I understood what you said, your lens still works, but only focus when you zoom in. Say if you want a 200mm zoom, you have to first zoom out to 75mm and then zoom into 200mm.

[@RealBesty]

Fan Song Photography Thank you. At any zoom point, the autofocus hunts but if it goes slightly too far it can’t come back - the end of the barrel will extend but not retract.

[@fsong00]

@@RealBesty Got it. This is autofocus issue. it is the circuit board needs to be replaced. Mechanics at this time it sounds ok.

[@RealBesty]

Fan Song Photography Many thanks. Sorry to use you as Tech Support… :)

[@fsong00]

@@RealBesty There are two boards, I am not sure which one to replace. If you don't plan to send your lens to canon and it is there collecting dust, you can send to me and I will try to see if I can fix it for you. If it is not fixable, I will mail it back to you. No warranty no obligation no liability no other related issues, just for fun. Only lens in North America though.

[@neilpinkett]

could you have just gone in from the other end first... without disturbing the ribbon connectors or does that have to come off as well

[@wasfiiwasfi]

Thank you

[@khunkyawmoetun2976]

good

[@onair7809]

Hello, a link of the brushes. Thank you.

[@fsong00]

Yeah, I had a quick search on eBay, it is really hard to find this kind of brushes now. If your brush is not totally broken, then I will recommend trying to straighten them out and fix the existing one.

[@onair7809]

Thank you very much, the central leg has been broken and it looks bad, I'll keep looking. A hug.

[@hubertndunyo4965]

Hi, how did you fix the brush at 10:11

[@fsong00]

You have to unscrew the brush and take it out, use a sharp clamp to put all the pins back to shape.

[@lalengkima7196]

👍

[@tristan_andrade]

I can’t seem to get the front element glass correctly installed And it doesn’t focus correctly

[@fsong00]

i dont see this issue. The trace should put everything in the right order. If can't focus, I suspect there might be something different that is broken.

[@wasif9838]

Finally i spoil my lens

[@fsong00]

Woo, I like your way of "spoiling" your lens!

[@DJROY-j5q]

Can i get a pair of new bruhses?

[@fsong00]

The best way is to fix the brushes if it is not totally broken. it is made of copper and it is flexible. Just take time to fix it. it does not have to be perfect. just align them and make sure each pin can contact.

[@DJROY-j5q]

@@fsong00 thank you so much. But my 1 pin is broken. Can i fix it by soldering? I need your help.

[@fsong00]

@@DJROY-j5q hmm. soldering is a choice. But it requires a lot of careful work. It also depends on where the pin broke. If it is just a small portion, you can use the scissors to cut the base a little bit and then try to pull the remaining pin down to make the good contact. Just some ideas.

[@DJROY-j5q]

@@fsong00 Is there any chance of getting a new pair of pin?

[@DJROY-j5q]

@@fsong00 or it will work without a small pin...I can send you pictures.

[@Danny-BigD]

at first he didnt tell you to take out the TWO SMALL screws at the start its around the RING

[@DemonKingWR76]

fuck the ribbon that connrct to the lens cut i miss up

[@MdRipon-ul4no]

😢😢😢

[@dnise274]

Get video.. Been needing to fix mines

[@fsong00]

Thank you for the comment!

[@raulleonardopachecoferrada4180]

Pésimo ya que tiene todas sus partes poco mas que desmontados.

[@СергейМаваши]

А собрал то по корявому, зум до конца не крутится👎🏽

[@hnisala]

I think it's time to say good bye to that lens.

[@fsong00]

It is an old lens. This video was made two years ago. and the lens was just purchased from ebay. I fixed it just for fun.

[@hnisala]

@@fsong00 Wow. I had no idea. Great work btw.

[@اغربمقاطعفيالعالم]

Thank you, but you have too many Thank you, but you have a lot of mistakes in explaining🥲This way to make my lens break down but thank you