Auto-focus locking up

[PhotoJunkieJen]

I was shooting some softball last night and out of the blue, the auto-focus on my less-than-year-old Canon 55-250 4-5.6 began locking up. Total grid lock. Wouldn't focus at all.
Since I didn't drop or hit it, is it possible I just messed with some camera settings (I already checked, I didn't switch it to manual focus). Or is a trip to the shop inevitable? (was hoping to avoid that one as I need the zoom this weekend).
What are the chances it's warrantied?
Help!

[sybren]

Does the focus still work when used manually? Have you tested the lens on another body, or another lens on this body?

[PhotoJunkieJen]

I don't have another SLR body to test that lens on unfortunately. However, I did try my Tamron lens on the same body and it worked fine... I guess that means it's an issue with the Canon zoom...

I found this on another website... though I'm not entirely sure what a focus ring is or where to find it. (I'm not a total newb, but I wouldn't call myself a professional either. )

"I was having the same problem last week with my Canon Rebel XS, and had my photography teacher take a look at it - apparently my focus ring was just stuck, so the camera couldn't focus properly. She pulled on it until it could spin easily and started working again, with no need for me to send it in to Canon for repair (which was going to be my next step). If you're having this problem and can't figure out where the focus ring is, just take it to a camera shop - they should easily be able to tell you if that's the issue, and fix it if so. "

I'm guessing, if one lens is working and another isn't, though, that this probably isn't the problem.

[PhotoJunkieJen]

Oh, and I forgot to answer this... yes, the manual focus still works.

[sybren]

You focus manually by rotating the focus ring, so I guess you've already found it ;-)

Take a look at the metal contacts on your body and lens, and see if you can clean them with a damp cotton swab. Be sure that they're completely dry before reassembly!

[Jim Bryant]

I carry a pencil with a rubber eraser.....that cleans the contacts just fine. But hold the camera body sort of upside down, so that the particles won't fall back into the camera.