But I have seen this happen when the stock power supply can't handle the better cards.
I tried installing a Geforce 770 video card in my HP HPE H8 1112C desktop. The computer would not boot up with the card installed. After trying everything I could think of I took it to Best Buy ( where I bought the card) and asked them to install it. They informed me that the motherboard had been flashed by HP to prevent the installation of 3rd party components. Has anyone heard of this before?