I just had my D7000 repaired by Nikon to fix a back focusing problem. It took me a year and 25,000 shots to notice that there was definitely a camera fault.
There were three reasons for my delayed discovery:
I had read plenty of chatter online about the D7000 back focusing problem so I was inclined to believe that my fuzzy photos were due to user error.
Most of my shots during that period were landscapes and I was able to dial focus in very deliberately.
Most of my shots during that period were taken with the 18-55VR and 16-85VR usually at f/8.
Only recently had I started shooting my kids playing rugby and soccer. Then the problem became very obvious. I was shooting with the 70-300VR wide open which is far less forgiving than the above two midrange zooms. It may be the case that the AF problem was more obvious because I was shooting dynamic subjects, that is, a combination of back focus errors plus focus tracking errors. On my test shots with static subjects I was still finding consistent back focus errors but not to the same degree as with dynamic subjects. A test rig for repeatable dynamic test shots is beyond my means.
I shipped the body to Nikon after they agreed that my test shots showed an AF problem. It was a week out of warranty so I wrote a letter pleading my case. Fortunately they covered the repair and return shipping at no charge. The whole process took 5 weeks. Of that 1 week was for shipping to Nikon and back to me. I queried the long delay with Nikon customer support because the online status checker showed the body was in the shop for 1 week and then the status changed to “Bill” for the next 3 weeks. I was told that the body was being thoroughly tested prior to shipping. I don’t know what they fixed. I had a repair code B2 (moderate repair, major parts replaced). The body serial number is 3128xxx.
My D7000 is back in my hands and delivered fantastic results last weekend at my sons rugby match. All’s well that ends well. I am $50 out of pocket on shipping charges and missed having my camera for a month. Fortunately my “obsolete” D50 was an able back up. I had thought of selling it. Boy, am I glad I didn’t. And that D50 just blew me away. It can take fantastic shots. My dud shots were all due to user error: I had forgotten how to use my D50. (mg)