well, if you are plugging in the cards w/o the drivers installed from AMD and expecting the monitor to turn on you may be mistaken... also, plugging the monitor in the mobo vga slot with video cards in the pci ports may not work as well, as i had this problem i think w my friends rig.  unplug the cards and get the monitor working like they did in the shop, then upload the latest drivers from AMD to run your 7970's.  Also tell your wife that she can be of help with this as two brains are better than one.  Always take a break, and ground yourself from static before working on the system.  I'm kind of a newbie myself but sometimes the obvious isn't obvious to seasoned miners.  Hope you are hashing away shortly...