Can't get computer to boot - Asrock X99 Extreme 4 + i7-5820k

I bought a Asrock X99 Extreme 4 + i7-5820k combo bundle from Ebay. I cant get it to work. I have tried 3 different power supplies, 2 video cards, 5 different RAM sticks (of 2 different types) and I can't get it to do much of anything. I installed a piezo speaker to get beeps.

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When I push the power button, a red light comes on near the bottom (I think this indicates which BIOS is running) and all of the fans come on, but thats it, no beeps. If I install a video without the extra power plug in, it constantly beeps, and if I remove the RAM sticks, it gives three beeps. Wondering if the CMOS might be messed up, despite pushing the CMOS reset button, I replaced the CMOS battery (the old one was at 3V, so I think it was fine), but now it wont stay on longer than about a second. When I push the power button, it turns on, then about a second later, I heard a faint click (like a relay?), and it turns off for about a second, then clicks again to turn on. This repeats over and over.

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I have unplugged everything from the motherboard in order to rule out anything, but every card and drive I've plugged in, as well as the case, was working fine before I put this board in. At this point, the only thing I have plugged in is the video card (currently a brand new R7-240 I bought to help troubleshoot), the ATX and EPS power cables, and the power button.

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I think this board is screwed but I wanted to try everything before I return it. Any ideas?