My lovely but clumsy wife dropped the 40mm Pancake not very long ago. It now does not register when mounted on my 50D or her T4i (ERR 01). However, it works perfectly on my 5D2. Why would this be?
Check all the contacts, make sure they're clean, none of them are bent or mis-aligned? Maybe one of them is just enough out of whack that some of the bodies don't make a good connection.
Also try focussing to as close as it will go, and then to infinity, see if something is catching or if the barrel feels 'off' at any point.
Access wrote:
Check all the contacts, make sure they're clean, none of them are bent or mis-aligned? Maybe one of them is just enough out of whack that some of the bodies don't make a good connection.
Also try focussing to as close as it will go, and then to infinity, see if something is catching or if the barrel feels 'off' at any point.
See if it works in manual focus mode?
+1
The lens isn't communicating with the body. Examine the rear of the lens carefully and gently rub a pink eraser on the lens contacts. Make sure no debris is left behind before re-attaching the lens to a body.
Here's a link to what the rear of the lens looks like.