Auto-Focus gone crazy

[williamdrew]

I just got my first DSLR in August, and my first lens was a Tamron 18-250mm. It was the only lens I had until a month ago. Just recently the auto-focus on the lens has partially stopped working.

If I have it set to auto, it only goes from one extreme to the other without focusing on anything. But if I manually adjust it, then the auto-focus will start to work once I get close to focusing on the item.

And when I have it set to manual, then the auto focus works.

Is this something where I just have to realize the auto-focus on the lens is shot, or is there a fix for it? Could it be a function of dust?

Thanks in advance for any help.

[prinothcat]

The Tamron has a warranty correct? It's probably time to use it. I suspect something mechanical in the lens. There is no legitimate reason why a lens which I imply from your post is only 6 months old should be failing.