Good news! I am currently writing this from my computer that was giving me issues. Let me tell you what happened.
TLDR/Others with same problem answer:
I swapped out my graphics card and motherboard and was still getting a series of error lights in a cycle of CPU -> DRAM -> VGA. There was no display on screen. Before this, and on a different x570 motherboard, I was getting a constant VGA error light.
I eventually got into UEFI by removing all storage devices. Inspect your drives, especially your boot drive for damage. Try reseating your SSD in the other slot(s). If this doesn't work after waiting a few minutes and your error lights don't go off,
try turning your computer off, take all of your drives out, then holding down power + reset button for ten seconds, then release. This will put you into a backup version of your UEFI/BIOS, in my case version F2 for the x470 Aorus Ultra Gaming. From there I was able to adjust settings to their default.
I set my RAM frequency to manual, but to the same frequency as auto. I/E I set it to 2133mhz, which was the same frequency as it was on auto. I did not touch my CPU voltage/frequency. I then was able to
save the profile, save and exit UEFI, turn my PC off after you get back into the UEFI screen, install the m.2 drive, boot again, and hopefully you'll be into windows.
Full Answer:
When I got home today, I took my PSU out of my system for manual testing. I used the multimeter and followed the video you linked. I tested everything in the video and everything else. Everything was up to spec and all the voltages were spot on.
After this, I tried running my system once again without any storage devices. When I removed my M.2 drive, I saw that there was a warp in it. I knew there was a warp in it before, but I must have disregarded it or forgotten it. Funnily enough, the system ran fine using this bent SSD for months, if not more than a year. I'm not sure if this was causing my problem or if it was the slot. The slots looked like it had a small dent on the armor.
Curved SSD Picture
To my surprise, after 5-10 cycles of the CPU -> DRAM -> VGA error light mystery, the error light section of the motherboard went dark for the first time in weeks. I turned off the system and connected it to a monitor, plugged it in, turned it on, and I was like a child on Christmas when I was able to get into my UEFI. It told me that the settings had been reset (I had cleared CMOS sometime last week) so I went through and set them all up and saved the profile. After this, I saved and exited and turned off the computer.
I put my m.2 drive only back in, but this time using the top slot and it booted into windows. Everything was well and the system seemed normal. I turned it off and went to go eat dinner.
When I came back, my PC was still only half put together, with used thermal paste on the heatsink and stuff inside of the computer being unplugged. I plugged everything in, put my second graphics card in (since I now plan on using it in SLI) plugged in the SLI bridge, and my SATA SSD. When I turned the PC on, it was giving me the same series of error lights, this time not displaying an output and not ending. I took out one of the graphics cards and unplugged the second sdd. Same lights. I take the M.2 SSD out. Same lights. Stumped.
Next, I held down power + reset to get into the backup bios. I was able to get in with no problems. I adjusted settings, but this time I set the RAM speed to 2133 instead of "Auto (2133)" Then I restarted to see if I could get back there. I could. I turned the computer off and plugged the M.2 drive in, and the system booted back up into windows. This time, I tried to gather as much info as I could while I had access to the OS. I ran a
benchmark when I got into Windows 10 the second time. It says I am running 3200mhz RAM, but I assure you that I am not.
I went back into UEFI to set my XMP profile and up the frequency on my CPU to 4.0Ghz. When I got back into Windows, I ran another
benchmark. This time it was a little..
<Mod Edit>. I'm not sure what happened but I ran the benchmark twice and I got the same weird results.
No matter what the problem is, I plan on purchasing a new boot drive. Probably a 970 EVO. If I'm receiving weird benchmarks with my SSD and the PCB is physically curved, It's probably not the best idea to continue using it. I guess that's what I get for cheaping out on my computer components O.O
I'm going to try setting up SLI again and see what happens. Thank you so much for all of your help, moral support, and patience with me! I know this is probably a weird problem to have. If I receive any other problems, I'll reply to your latest comment again. Thanks again!
Edit: TLDR/Best answer