Just checking. Intel doesn't use a 4beep code, but it does use a 2beep,pause,2beep then continue to boot. That beep code is video error, no gpu installed. The only way you'll get that error is if there is an actual gpu installed, it gets recognised as the x16 port being populated, but either the card wasn't fully seated correctly, or no power was supplied to the gpu. So you get the beeps, bios switched to secondary video source (the igpu) and pc should have booted, only you can't see it since the monitor is plugged into the gpu not the motherboard.