So I am in the middle of an upgrade, and my computer only boots with the exact set of hardware components, I can't plug in another sata connector for fan hub, or a new drive. I had taken a few components off, and tried to reboot it, when I originally came upon this problem. I put the components back in - a hard drive, and fans but the problem was still the same. I took out the hard drive, and it booted fine. I only have an nvme and hdd. I assume that was because of conflicting boot priorities? The computer's lights will flash on, and then off, within a second. Am I just missing something really basic? I don't think I have the psu maxed out. The computer otherwise works fine, and boots properly. I hope I'm not being an *****. Please help me if you have any inclinations as to what the problem may be.