20D focus problem

Lately my 20D has a problem in focusing, it takes forever to focus, and sometimes not possible at all even at good day light! And when I shoot pictures, sometimes it does not work, complained ERR 99, waht is that?
Thanks.

I used to get the err 99 thing now and again on my 20D when i used my 500.Dont know why it did it, but i just did the battery thing.

What lens are you using ?.

I am using EF-S 17-85mm lens, I have cleaned the contacts, still the same. But when I used my macro 100mm lens, it's ok.
I have used this lens for 3 years and there is no problem, the problem started yesterday.

sounds like the lens to me.

When I was seeing Err99s, it turned out to be a sticky aperture diaphram on my Tokina 24-200 lens. See if you still get the errors when using the lens wide open.

Try cleaning the contact points between the lens and the camera

I have cleaned the lens contacts, still the same. If it's the lens problem, what should I do? Will a service make it work again?

cbtoday wrote in post #4174459
I have cleaned the lens contacts, still the same. If it's the lens problem, what should I do? Will a service make it work again?

That's their job.