Any reason for a brand new 50mm not to work?

[WI New Guy]

Hi again everyone.
I posted a week ago or so wonering about an AF problem. Nothing has been resolved, and Canon now has the camera. They want $211 just to see what the problem is. I bought this used and the original owner says he never had a problem.
Here's my question. Is there any reason for a brand new 50mm 1.8 II, not to work on a 40d? The original owner says he has the same lens and it worked fine. He says the 2 lenses that don't work for me (the 50mm, and a 18-55) are the problem. I say since the lenses work on my XT, the camera is the problem.
I feel like I'm being taken here. Any help would be great.

 

[NucleaRR]

I know it may be simple but...

Have you ensured that the contacts are clean on the camera and the lens?
I had this same problem after a trip to Cancun. Some how I had gotten some dirt and hand grease on the camera's ring. I wiped the ring off with a damp lens cloth. Then I used a white eraser and 'erased' around the ring. I wiped the lenses off with the same damp lens cloth. My lenses immediately began working again. If you don't have a white eraser you can get them at most craft stores. Be careful to not get the eraser shaving in the camera body. White erasers tend to give off less eraser shavings, which is why I used one.

Good Luck.

 

[WI New Guy]

When I first called Canon they suggested the eraser thing for the contacts on the lens, and I did that, but as far as the whole ring, no that I didn't try. And Canon never suggested it.

 

[AlexColeman]

Might be in the body if two lenses don't work, try the above as well.

 

[Seefutlung]

I'd say it's the camera. Try the lenses on another 40D (say at a camera store) ... if they work on that 40D then get your money back.

Gary