Take it back out and see how it goes? If it works, go into the BIOS and make sure it is set to allow 'auto' or 'detect' graphics output method. It might still use the onboard output. You could try ...
An HP spokesperson has confirmed to us this afternoon that the company will be shifting its strategy around the Compaq brand starting sometime in 2013, eliminating “HP Compaq” phrasing altogether and ...