Recently, I upgraded my GPU from an HD 7770 to an HD 7970, and I noticed I was getting FPS drops in games. I figured the VRMs were overheating on my old board (ASUS M5A78L-M LX V2) so I got a new board. A Gigabyte 990FXA-UD3. Apart from the unrelated issue of a winows crash on startup, which was fixed by switching from AHCI to IDE to boot and install drivers, the only seemingly minor issue was that I could no longer get as many FPS on lower settings in CS:GO as I could before. I could get more on maxed settings, and I got 3X as many FPS on Furmark, so it was an issue I was sure i could get to the bottom of.
BUT: The next day, I tried to power my PC on, and nothing happened. The fans spin, but there is no HDD activity, no POST screen (I guess...I dunno cus i got no picture on my screen) no beeps from the little case speaker...nothing. just fans at low RPM. I tried resetting CMOS (though shorting the pins in the dark with a screwdriver was tricky and I dunno if I got them. I'll try again this afternoon using the jumper from my old board, if it fits) I tried swapping the RAM around, putting it in different slots, trying one stick at a time, in different slots. I replaced the GPU with my old one, and all that happened was that the fan's RPM would kind of pulse. I'd had that problem before, and it was a failed PSU, so I went and got a new one. (The old one was a 500watt, so was cutting it pretty close)
Anyway, I just installed the new PSU, and I'm getting the same thing. I only plugged in the drive with my operating system on.
I need to try clearing the CMOS properly, and I need to maybe try different RAM, though I don't have any spare, and it worked fine for a day.
But...it's looking like either the board just died after 1 day of use, or the CPU died after one day in a new board. Both of which seem kind of odd. I still have my old board, so i can put everything back on that to rule out the CPU and the RAM, but I'd prefer to check first, to see if there are any checks i can do without having to strip everything outta there.

I didn't find the right solution from the internet.
References :

https://www.computerforum.com/threads/is-my-new-board-dead-already.240825/

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