How do I troubleshoot a new z790 Taichi Lite£

I have an update. Things point to the original 1.06 BIOS not supporting Raptor Lake Refresh. Now I find there is no FLASHBACK feature.


This post hasn't gotten an love .. perhaps now? I have also reached out to Tech support. Would love to get my $2k worth of computer parts working ...

It's been so long since I built a computer I might as well be a newb. Where do I begin?

All new, just unboxed:
z790 Taichi Lite
i7-14700k
Trident z5 ddr5-7200 16x2 (sockets A2 and B2)
SSD (from previous i7-9700-based build with my Win 11 installation)
Seasonic Prime TX-1000 and
XFX 7800 XT

Main mobo power, aux mobo cable (2) connected, video card cables (2) connected. Basic fans, including CPU cooler, are connected

I power on the PSU and the mobo colorred LEDs under one of the SSD covers come on. The mobo power and reset buttons light. I press the power on button on the mobo and the PSU fan spins for 2 seconds. I see no other lights than the colored LEDs under one of the SSD covers. No fan other than the PSU spin. I have already unplugged the PSU and pressed the CMOS clear button.

What is step 1 in troubleshooting? Remove the video card and check if it posts?

Thanks,
Jeff