Is my af failing??

I have a sigma 105 macro (the older one not the newest)

Tonight I saw a cool spider in the web and went to take a pic. AF started not working right. I thought maybe I was too close and backed up. Then it started making funny sounds.

It sounds like a bunch of gears turning, or something spinning hard.
It kinda focuses some but wont do the "final focus" to get the fine details.
Sometimes it wasnt focusing at all.

Is it light?
Is the AF failing?

It's hard to tell....it could be because of poor lighting or some type of AF issue. Give the lens a try in bright lighting with a nice contrasty subject and see what happens.

Ok I will do that tomorrow. I tried it tonight outside (it's dark) but it was right under a porch light. when I brought it inside under the dining room lights it did the same thing. I will give it a go in bright daylight tomorrow.

Were you shooting in LV mode?

Hi no, I use manual and the "old way" I took it outside today full sun 12:30 and same thing. It sounds like a bunch of gears dying when I push the button. I switched it to manual and I dont even get the AF confirm lights.

How expensive is that stuff to fix???