Lens Trouble

I thought I'd treat myself to a new bit of kit, I'd been saving for the last eight months, didn't I deserve to?  It was clear what I was missing, a macro lens.  I opted for the Tamron 90mm, a very sharp lens and not extortionately priced, what more could you want?  So today I ordered one from a company, which conveniently turned out to be local, so I picked it up in person which saved on postage.  Ah the excitement of new kit!  With the longer days it was still light when I got home, so I had a quick test of it in the garden.  Whoo what a lens!  Sure the focus hunted a little, but it was incredibly sharp, and at f/2.8 the depth of field was as shallow as you like.  I was impressed.

I took about one hundred or so images of random gardeny stuff and then I encountered a problem.  After switching the camera to MF there was a clicking noise as I turned the focus, changing back to AF, still clicking, back to MF 'click click', back to AF.... and the focus has stopped working.  Ah.  The camera is no longer registering it to be an auto-focus lens.  Potentially problematic. Maybe there was something wrong with the camera connection?  A hollow hope yes, and one which was diminished as the lens failed to respond when tried on a different camera body.  Huh, change from manual focus back... still nothing.  It was 2nd hand, but even so... the rest of the lens is in prime condition, so why has the auto-focus gone?  For now an unanswered question.
 It was some relief I had bought it from a company, I should be able to take it back to be repaired, as it really is a beautiful piece of kit.