MacPro black screen on startup

I Have a 2009 MacPro tower. Worked fine two weeks ago when I shut it down, now when I turn it on all I get is a black screen.

I hear the boot up chime, I can tell by listening to the HD that OS X loads and gets to the login prompt. I've reset pram, held down shift on boot up, reseated the video card. The monitor acts like it's not getting a signal. Tried hooking it up to a tv, same result.

Any ideas?