I am lodging a complaint to Canon Hong Kong regarding the abnormal slow down/failure of Ultrasonic Motor of EF 70-200mm f/4L IS USM, S/N: 0050XXX, purchased in Sept 2012, I discovered that the focusing speed is significantly slower than my 24-105, so I took it to the Canon Showroom in HK 2 weeks ago, to compare it with the EF 70-200mm F4L IS on display. Canon's engineer immediately identified that this is due to motor failure. A repair fee of HK$1.6K, with 15% discount.
I researched on this issue and found a lot of reports on similar problems posted on online forums in USA, Hong Kong, Taiwan, China(see hyperlinks below). There have been numerous cases of focusing slip of USM of the same model, especially on lens produced in 2011-2012, UZ & UA code, (my lens is UA). Most report that when the lens are held 90 degree upright, the AF would stop working. The focus speed would slowdown and it would worsen over time.
Apparently, this is DESIGN FAULT, or QUALITY CONTROL
A local small forum has 32 users reported the problem and get it repaired, 10 users confirm a fee about US$120 (incorrectly typed 1200) is charged. http://www.dchome.net/forum.php?mod=viewthread&tid=1161908&extra=&page=1
I would like to urge Canon to recall the batch globally, get the motor parts replaced! Similar problems have happened to Nikon’s D600. Following a complaint and a file of lawsuit in California, they recalled the faculty batch globally.
I am making informing local newspaper and gathering S/N, Batch code and repairing date for further action. Can anyone doing the same in the USA?
S/N number: ___________________
Batch Code: ____________________
Reparing Date: __________________ (as accurate as possible)