No POST (Just a blank screen)

A friend is building his first computer, I'm helping out. Although I've repaired more systems than I can count, this is also my first build from scratch.

Processor: Intel i7 2.66 GHz
Memory: Corsair 2 GB x 3
Board: Gigagyte EX58-UD5
Graphics: Asus branded ATI Radeon HD 4890, 1 GB DDR5 RAM
Monitor: Samsung 24" HDTV / PC Monitor 1080p

I mention the monitor because i'm not convinced that the system is the cause. I've never dealt with a HDTV/Monitor combo before.

Okay, so we turn the computer on, nothing happens. Blank screen.

In regard to this Asus ATI 4890, I recall placing the card firmly in the PCIe x16 slot, and connecting a power supply. Does this card have 2 power supplies? We tried to RTFM, but the user manual sucks far beyond the usual poorly translated user manual. It's just a 2 page generic graphics card manual with nothing specific about this particular card.

Also, could the issue be the TV/Monitor: Is it defective, or have we connected to it incorrectly? What is the correct external connection (PC vs DVI vs HDMI vs (whatever)). We constantly try to confirm the settings, and the freakin thing goes into standby while we're using the settings panel.

So, those are my two guesses. Any clarification on those guesses, or other places to look, will be much appreciated.

Thanks