Canon EF 85mm f1.8 auto focus issue

[kanon]

Hi, my EF 85mm f1.8 isn't able to auto focus – it is just jumping back and forth nervously few times a second. Manual focus works ok. Has anyone had the same issue and what could be the problem?

[rcoppola]

I've  the same issue with my Canon 85mm f/1.8.  The autofocus is jumping forth and backwards.  I've sent to the authorized thechnical assistance.  The answer was:  we are sorry, but it will cost you $ 210 to rapair it.  (a new one lens at B&H Photo costs $ 349).

The auto focus just deteriorate after 3 years, even with a low level of use and no accident, fall or colision.  It's a shame.  Consider other brands. The Canon 85mm 1.8 is really not reliable. 

[kanon]

I forgot to report here, but I had exactly the same answer when I took mine to be evaluated. Motor was broken. So I use it as a manual focusing lens.

I still have got nice portraits with the lens, and with 5dmkiii you'll get a confirmation when the focus is set correctly so it is totally usable lens this way too.