Canon 24-70mm 2.8L USM Second Series Diaphragm Group Replacement

Today we will analyze this interesting repair we just did:
The replacement of the aperture group due to Err 01 on a Canon 24-70mm 2.8L II USM Second series

The Problem

All Canon 24-70mm 2.8 L USM either the first or the second series, who sooner or later, will show this flaw. These lenses starts giving the error 01 (Err 01, Communication between camera and lens is faulty. Clean lens contacts.) while using the lens or after being unused for a while. This very generic error has an infinite number of possible causes. It means that in that moment the camera is failing to communicate with the lens.

Unfortunately cleaning the lens contacts it’s almost never the solution. It is therefore necessary take the lens to a laboratory to return to using it correctly. On this specific model, the error is almost certainly due to a communication problem given by the diaphragm group. In fact, the aperture unit is no longer able to receive informations from the camera , for this reason will stop working. In some cases the lens continues to shoot with the aperture open, in other cases even at 2.8 it is no longer able to shoot.

This problem happened to our client who, on his first shooting after a few months’ break, had to stop shooting with the 24-70mm 2.8 L II USM. You can only imagine the disappointment of having to go home without having recorded any photos in its memory card!

The Fixing

Knowing this lens and this specific flaw very well, the repair was quick and easy. Once disassembled we immediately found that the error 01 of the Canon 24-70mm 2.8 L II USM was given precisely by the aperture group. This did not move under any circumstances, even when the camera required it.
We therefore had to replace the damaged diaphragm group with a new one and reassemble everything.

The Result

With our intervention the Canon 24-70mm 2.8 L II USM is back to work exacltly like before the break of the aperture group.
Now the lens shoots correctly at all apertures, from F2.8 up to F22!
With the intervention , we also checked the full correspondence of the focus. We also cleaned the dust inside the lens.

The fixing of Canon 24-70mm 2.8 L USM Second Series