Dead output?

Hardware Hub GPU
1

Alright. Background info on setup:

3 monitors:

  1. 27", D-DVI output @ 2560x1440 [Shimian power!]
  2. 23", HDMI output converted to mini-display @ 1920x1080
  3. 21" DVI output @ 1600x900

2 graphics cards:

  1. EVGA GTX 480 1.5gb memory
  2. Some random, shitty nvidia card that's irellevant as far as I can tell.

the 27" and 23" are connected to the 480 and the 21" is connected to the crap card.

Everything was working fine until today, when I went to get on the computer. All of my monitors except the 23" turned on, and eventually the OSD informed me that there was no HDMI signal. At first, I thought I hadn't re-connected the display, so I checked... and, of course, it was connected.

I ran out to my Jeep, and grabbed my MBA (Haswell, don't shoot me maybe?) and HDMI adapter. Hooked it up and bam, it works fine. I'm pretty lost. All of the settings are fine in Windows, so I'm wondering if it's possible for an output to somehow die, or anything like that.

Thanks for your time. 

2

Just wanted to update this... my power went out last night, and when I woke up and turned on my system... bam, 3rd monitor works again. No idea why.