Typical bios setup for access to other video besides on-board is "suppose" to return to default should the video card be removed. Should it not do this, then using the clear CMOS pins will return bios back to defaults and then return to allow to on-board video.
What you can do, is simply use the on-board video and finish the install build. Do it 100% for everything minus the new video card. Get all OS updates, drivers, bios, everything yada, yada and finish it. Once done and it works w/o any hassles and you're happy, then try the new video card install. Of course, have the latest OS drivers available and follow the instructions for its install as provided by its manual or guide. if it fails then, either improper power connection or not enough power or it is a bad video card. You have to figure that out as you're there. Again refer to manual to verify proper power connections. Don't take anything for granted here, assuming is not proving. Reverify your checklist and then re-try the power-ON test.
Oh yes, be sure its fully seated in video slot(primary is dual/SLI) and video cable is connected to "primary" video output port and/or correct one. It may seem like I'm hedging here, but video cards are such a PITA if you can't see a display yet no apparent error beeping or clue. Sometimes, as I've stated you have to try in a known working PC to see if it works at all. Next, inspect all power cabling is correct and proper(found bad crimps) and the PSU is over-whelmed because its a dual-rail setup vs. a single rail.