Canon USM 100-300 'gone floppy'

[Paul Nellist]

Hi folks, a close friend of mine has just come to me with his lens...'its broken' he says!!!!
Sure enough it is, the zoom ring has failed and now the lens just flopps about when the camera is tilted down or up.

Does anyone know of a way to strip this lens (Canon USM 100-300)...maybe a link to a site???...we are both sure it is something and nothing that has gone wrong internally...hopefully we can give this old lens a second breath...

Thanks in advance everyone..

Paul...

 

[markw08]

I assume there maybe some sort of gear mechanism inside... :shrug:

 

[Paul Nellist]

Yeah that is what were thinking but dont want to start butchering if we can find a proceedure to strip it in the correct way!!....hence this thread, you are the guys that know afterall....

 

[andyred]

Hi

Don't know of a link to that lens, but I do remember seeing a link on here somewhere showing how to strip a different lens.

On the top of the lens - the black ring around the glass, where the writing is can be very carefully lifted off and you should see a few screws underneath, which allow you to begin to strip it down. BUT, you do so at your own risk and be very carefull with anything you use near the glass, one slip across it and it's scratched.

Can't seem to find the link at the moment, will keep searching.

Norfolk Camera Centre are worth a call if you don't want to tackle it yourself

 

[MisterE]

I've seen a video somewhere of a similar lens stripped down. It generated a huge amount of parts. I've also stripped a broken Pentax 28-80 AF lens just for the fun of it. I've been taking things to pieces and mending them all my life, but I would never have got this lens working and back together. And that's without removing the plate which released a pile of springs and balls with no idea where they came from. I'd only attempt it with a view that the lens was disposable.