Static Is Killing Me, Using The Scientific Method Options

[sfsurfer]

I'm wondering if some of you might be able to offer me some suggestions as to eliminate some static in my recordings.

My Setup:
I've got a 800 MHz G4 running 10.3.2 with 1.5 GB RAM and an Echo Mia PCI sound card which is connected to a Behringer Eurorack UB1202 mixer which has a single Shure SM58 microphone plugged into it. I'm using Deck for all of my recordings. I have all of this plugged into a UPS, which is then plugged into my wall.

My Problem:
Anytime I record with this setup, I get frequent static noises. I bought the UPS because I thought that the power from the utility company was causing the problem. After hooking up the UPS, I found no change in the frequency of the static. However, when I record using the cheap little microphone that came with my computer, I get no static on the recordings. This suggests to me that it is my setup with the sound card, mixer and microphone. What's really frustrating is that I avoided getting a USB interface for recording so that I wouldn't have the seemingly common static problems associated with USB.

My Question:
Is there an easy way for me to figure out where this static is coming from (within the sound card, mixer or microphone) without having to buy any more equiptment? I don't have access to another set of these components, so I can't just swap other ones in place of mine to test. I also can't return the sound card, mixer or microphone, so I'm stuck with them. Is there a likely culprit that is causing my problems? Has anyone else solved a similar problem? Or does anybody have a better suggestion in how to connect a XLR plugged microphone to a computer for relative cheap? If so, I've got a virtually unused sound card and mixer for sale cheap!