Canon EF 24 - 70 mm F2.8 L USM Lens problem

[Nicolas Claris]

I own this lens for about 4 years now.
I did send it to Canon pro service in Paris a few months ago for some minor repair (loose rings).

I usually use autofocus, but some days ago I needed manual focusing, so I pushed the small button to MF (manual focus), then the camera (1DS2) refused to shoot as it does with all other lenses (so no tricky PF or cfn here).
Of course I cleaned the electrical contacts of the lens, with no success…

Before I'll send it back to Canon, it means more than a week without it, and I can't for now, does anyone has an idea of anything to check?

Thanks

[Paul Bestwick]

sounds like maybe the camera would not fire because it was thinking that it was not achieving focus.
Put in back in AF & see what happens... (if you have not already)

[Nicolas Claris]

Hi Paul

sounds like maybe the camera would not fire because it was thinking that it was not achieving focus.

Exactly!
it happens when the focus is toward an area like the sky (no contrast), if I move to an focusable area (when auto) the camera will fire

Put in back in AF & see what happens... (if you have not already)

did that plenty times!

GOT IT !
the AF/MF button is just blocked on AF wether you move it to MF!

Thanks for the help, at least, I know what happens!

[Nicolas Claris]

Finally I did bring the lens last Wednesday to a local camera repair (a known person for excellent quality service).
And got it back yesterday (Friday):
The AF/MF button was just not internally connected!

This mean that the Canon repair Center in Paris forgot to plug that damn button when they made the repair. Unbelievable! bud sadly true…