I bang up and use my 1Dx's pretty consistently. I noticed I had some AF misses which were unusual at a track meet 12/12. So since I'm a Platinum member for CPS I sent them in explaining the problem.
On 1Dx number 1 the following was found: "Your product has been examined and it was found that the part did not operate properly because the mirror did not operate properly. The part was replaced and product functions were confirmed."
On 1Dx number 2: "AF assembly was out of position causing inaccurate auto focus. Electrical adjustments were carried out on the AF assembly. Product functions were confirmed. Adjusted exposure and ffd, basic focus and shutter speed. Updated firmware. Cleaned C-MOS and checked to all factory specs."
Whew!
On 1Dx number 1 the following was found: "Your product has been examined and it was found that the part did not operate properly because the mirror did not operate properly. The part was replaced and product functions were confirmed."
On 1Dx number 2: "AF assembly was out of position causing inaccurate auto focus. Electrical adjustments were carried out on the AF assembly. Product functions were confirmed. Adjusted exposure and ffd, basic focus and shutter speed. Updated firmware. Cleaned C-MOS and checked to all factory specs."
Whew!