Unable to power on?

Looking at your board with the CPU at the top and the slots located at the bottom your power switch should be connected to the last 2 pins on the top 4 pin row of the front panel header, the reset switch should be on the last 2 pins of the 5 pin row beneath it. The Hard disk indicator should be connected on the first 2 pins of the bottom 5 pin row and the power LED to the first 2 pins of the top 4 pin row.

Edited my post, somehow forgot about it. It's an Asrock X370 Taichi. The LED on it is slowly fading in and out which I assume means it's powered up. The LED on the Cryorig would also light up if the LED pin header were plugged in, which it isn't because particular complications that I want to work out first.

Edited by Haku - 18 Dec 2017 at 2:44am

Aww! I hate to see people starting with so much enthusiasm and then left with that bitter feeling.

What else I can suggest? Here we're going into more 'esoteric' thoughts.

- Bad PSU? Can you borrow some other PSU?
- CPU not seated properly?
- CPU cooler not seated properly? Even though I don't believe it can build heat that fast.
- Mobo shorting out somewhere, e.g. touching chassis somewhere? Try running it in minimal configuration on a wooden surface.
- Fixing screws too tight?
- I've seen chassis fan screws (the thick ones, for plastic) chipping out metallic splinters from the chassis. These splinters later shorted out some surface mounted IC. Yeah, that happens too.

I don't know what else could it be. Since you can't even get to POST/UEFI there is no debug code to see. This means the problem is rather more mechanical or electrical than anything else.

One last thing, with the front panel header stripped, you could try to mimic the power button with a screwdriver. This should sort out if there is a problem with chassis' power button. DANGEROUS if you don't know what you're doing. Not very elegant method but sometimes that's all we're left with.

If none of this helps, I'd suggest you RMA the mobo and/or the PSU. Fingers crossed!