I believe that is the display telling you that it isn't getting any signal from the card.
Try manually defaulting the mobo CMOS, usually by shorting pins on the mobo, check your manual for directions.
I hate to say this, but you may need to try the other mobo. It probably wasn't booting due to a short, but it didn't get fireworks so it may be ok. The other option is to take the components down to the local PC shop and have them test them all, assuming that they don't want an arm and a leg to do it.