need help fixing canon 50mm 1:1.4

today i picked up a canon 50mm lens 1:1.4. i paid 100 dollars for it. the problem with the lens is that it will not focus at all. and the focus ring feels like its full of sand. i did find a video on youtube and took it apart cafefully and clean off all the sand that was in the lens. and there was alot. but even after putting it back together i have the same problem. any advice or is there anyone that can repair the lens for me without costing me an arm and a leg?

You need to take it all apart. The focus ring has 2 grooves in it that have become sloppy and need to be put back into place. We have a thread on it somewhere. This is the pieces when I took mine apart and repaired it.

Photo from Chet's gallery.
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thats the video i followed. i just took it all apart again and im in the process of putting it back together but it still doesnt move. how much would you charge me to fix this lens?

angelusnhc wrote in post #18883748
thats the video i followed. i just took it all apart again and im in the process of putting it back together but it still doesnt move. how much would you charge me to fix this lens?

Does the motor actually work?

Chet wrote in post #18883752
Does the motor actually work?

idk honestly. i attached it to both of my camera's and it wouldnt do anything.

At some point it makes more sense to cut your losses and pick up another that works. On the F/S forum there are a couple in the $200 range. Probably get it for a few $ less than that.

It is likely the focus rails that are deformed.

This is the piece that needs work I presume.

https://www.ebay.com …424662916?redir​ect=mobile

When you say sand I worry about salt spray and it's corrosive nature. The fact you don't hear or notice it trying to focus concerns me. The circuit board or motor may be no good.

Check the aperture with your depth of field button to see if that is working. Either the motor or the circuit board could be dead due to salt water.

A new, revised metal focus ring with both collars is about $60 from Canon. I used that to restore my 50/1.4
You'll need to re-lubricate it to get it working better than without lube (if you can solve the electronics).

I personally don't buy parts off ebay if I can help it. Sometimes they charge 3 times the cost and sometimes their counterfeit. I prefer to buy them from Canon parts.

Lastly, it is possible at times to reassemble lenses without most of the components to check things (franken-lens). A deformed focus ring could be putting enough resistance on the motor to keep it from turning at all.