It honestly could be either the PSU or Motherboard... I still think it's the motherboard... I hate, and I mean HATE, ECS. Lousy tech support, shitty products, high failure rates. Avoid like the plague. I know two different people who to cut costs go with an ECS board that had similar features to an ASUS at 1/2 the cost. One had to RMA four times before he gave up and got an ASUS, and the other one had his RAM, CPU, and Video Card all killed by his board. Dead, as in won't work in another PC period.
Do you have a friends PC you could test each out in? See if your card works in his mobo, or see how your PSU works on his rig?
I would honestly just list both on craigslist really cheap and get these instead.
Motherboard - http://www.newegg.com/Product/Product.aspx?Item=N82E16813131795
PSU - http://www.newegg.com/Product/Product.aspx?Item=N82E16817371030
Video Card (If you want to play games at better setting) - http://www.newegg.com/Product/Product.aspx?Item=N82E16814161363