[solved]New build not starting x370 taichi

evilben, I would suggest doing a Clear CMOS.  Then try removing all but one memory stick and make sure the last one is properly seated.  Make sure your CPU power cables are correctly plugged (especially 4-pin CPU) and are CPU not PCIe.  PCIe are for video only.  Remove all drives and try.  Please let us hear.  Tell us about your CPU cooler.    Enjoy, John.

OK, evilben, unplug all but the CPU and one stick of memory.  You will obviously not get a picture but see if it gets further.  I suggest you investigate a speaker, so you can hear beep codes.  I assume you do not see Debug codes.  Please do try multiple memory slots with one memory stick.  Next, remove the CPU and check for bent pins and thermal compound on the pins.  Enjoy, John.

That is odd. You're getting the normal LED behavior before you press the power button.

MisterJ meant these 2-wire PC tweeters that are attaching directly to the mobo, not some external speakers.

Your PSU is also well-regarded and its cable naming is among the best I've seen. Most likely you did all fine there.

2 things worry me here: RAM & GPU. 32GB RAM can prove too much for a Ryzen, IF it's clocked high enough by default. Ryzens are notorious for how picky they are when it comes to RAM. Try only 2 sticks in A2 & B2 slots.

You can also put the GPU in another PCIe slot. Tripple-check GPU power as well. Try HDMI and DVI cables if you have these.

CMOS clear is mandatory after each component re-seating or change.

Please try this as well - get the mobo outside the chassis and try to boot/POST with the bare HW minimum. Care for a non-conductive surface to place the mobo on.

You NEED to clear CMOS every time you so much as touch a component, let alone replace/re-seat it. Doing so you are forcing the mobo to enumerate all hardware again. That's a very important thing.

Clearing CMOS is best done with PSU unplugged, CMOS battery removed, CMOS jumper to CLR and press the power button for 10s to drain the capacitors.

I am assuming that one of the items in the motherboard box was the multi language Quick Installation Guide.  Look at the "Motherboard Layout" diagram, item 21 "Power LED and Speaker Header SPK_PLED1".  Then look at section 2.6 "Onboard Headers and Connectors".