Canon has identified an issue with some EOS-1D X
and EOS-1D C models.
The affected cameras may have problems with AF searching but not locking onto the subject, and the image shown in the viewfinder being unsteady or blurry.
The problems above are caused by 'inconsistency in the amount of lubrication which has been applied to the driving mechanism, which is easily resolved', Canon states.
Only certain models are affected:
EOS-1D X: If the sixth digit from the left of the serial number is 1, 2, 3, 4, 5, 6, or 7.
EOS-1D C: If the sixth digit from the left of the serial number is 1.
However, if your camera has an 'A' mark in the battery compartment, or a black mark on the silver bracket in the battery compartment, then your camera is unaffected even if it has one of the above numbers as the sixth digit from the left.
Canon said "A countermeasure has been implemented in the manufacturing process, so units produced going forward will not be affected. We are proactively informing customers and offering a free inspection and repair of their product as a preventative measure."
Canon say potentially affected cameras will be inspected and repaired free of charge. More information can be found on the Canon Europe website:
Canon EOS-1D C
Canon EOS-1D X