Thanks for the reply. I'll try to answer everything you asked.
How long have you had this setup? Is this a recent issue, or has this build always had this problem?
Brand new build I put together this week. I have had one of the 470's for a while now, just got the 2nd one this week with all my other new hardware.
Does this problem prevent you from seeing the BIOS or POST screens as well?
Yes, it displays nothing when this happens.
Does the monitor go into standby mode during bootup without showing anything at all? Or is the monitor "ON" but showing a black screen?
With everything turned off the light on the monitor is orange. When I turn the computer on it will turn blue then as the computer boots up and it doesn't get any signal it will turn back to orange. Not sure if that is standby though.
What kind of monitor are you using, and how is it connected? Have you checked the connections between the video card and the monitor?
Acer G24" G-24. Connections are fine. But I'll try switching them around to see what I get.
You could also try switching the two GTX 470's into opposite slots in case one of them perhaps has an intermittent issue with the video output.
OK, I'll give that a try as well.
It's also possible the PSU could be an issue if it for some reason isn't outputting enough power for the two cards at bootup.
Wouldn't that happen all the time though if that were the case? It's a brand new PSU and should have plenty of amps to handle this setup.
Thanks again for the suggestions.