Err 99 and Autofocus Problem with Canon EOS-1D and EOS-1Ds Mark III

EOS-1D Mark III/EOS-1Ds Mark III: Abnormal Mirror Operation (Err 99)
Thank you for using Canon products.

We have discovered that abnormal mirror operation occurs in some EOS-1D Mark III and EOS-1Ds Mark III digital SLR cameras. Accordingly, we would like to provide information about the details of this issue and how it can be resolved.

We offer our sincerest apologies to customers using these products who have been inconvenienced by this issue. Canon always strives to provide the highest quality products to our customers, and we spare no effort in our quality management to make sure our customers can use our products with confidence. We hope our efforts will earn your understanding.

Phenomenon
The mirror does not operate even if the shutter button is pressed and the following message appears frequently on the camera’s LCD monitor.

‘Err 99 Shooting is not possible. Turn the power switch to

and

again or re-install the battery’

Affected Products
EOS-1D Mark III and EOS-1Ds Mark III digital SLR cameras

MORE DETAILS:

Err 99 and Autofocus Problem with Canon EOS-1D and EOS-1Ds Mark III | DigitalPixels.net - Photography Blog