Power Help Please (2 replies)

Okay, so I'm totally new to 3d printing and my only background is in programming. Answers will definitely need to be "like I'm 5"...

So I finished putting together a Prusa from MakerFarm, [www.makerfarm.com], using the prebuilt RAMPS 1.4 kit. I am powering it with the USB connection and one these 12v 30a power supplys:
[www.newegg.com]

Loaded it with the Sprinter firmware and can successfully connect to it with Pronterface, but that is where the success ends. Nothing moves, no humming, nothing at all.

So far my troubleshooting has consisted of:
Tested the terminals from the power supply and they are giving 12v.
Removed all motor/hot ends/thermistor connections one at a time, no change.
Removed everything leaving ONLY the X-axis motor connected, no change.

Here is the console output from Pronterface:
Connecting...
Sprinter
1.3.22T / 20.08.2012
start
Printer is now online.
SD Start
SD init fail
Soft PWM Init
Planner Init
Stepper Timer init
Free Ram: 4158
Plan Buffer Size:1152 / 16

So - where do I go from here? I'm guessing the power supply is the issue, but I'm not sure where to start looking for issues. Open to any ideas. Let me know if I should post any pictures or additional information. Thanks!