Since no one helped you out... Ill try and "point" you in a direction where ypu can get a solution.
1. Just remove videocard and blow out the plig with some air (on mobo and the pins on card)
2. Make sure you plug in the card properly as well as you power connectors are in al the way/clean.
3.if able. Try another video card in slot, to narrow down you issue.
Of problem persists, contact asrock. They should give you trouble shooting help.