Double check your fan wires and make sure the RGB leads as well as the power leads are connected.
I forgot to connect the main fan header. Time to install windows

Double check your fan wires and make sure the RGB leads as well as the power leads are connected.
I guess someone hasn't built a pc in quite a while then![]()
Built my first Ryzen system a couple years ago and knew it had to do the memory training on first startup, I also happened to update my bios after installation so thought I might of ruined my new pc. Nope it was a good 5+ minute install (all black screen).
manually set the speeds and timings and see if that does the same
Is the bios up to date?
If so, then I would suspect that the CPU has a weak memory controller that can't do 6000 mhz.
It's rare, but can happen unfortunately and sounds like you may have lost the silicon lottery
More issues now unfortunately.
If the only variable is expo that changes then most likely its a CPU memory controller issue. You can try increasing the voltages but I guess the best way is just to return and get a new one. In theory, expo is an over clock so there isn't any guarantee that the CPU will run it