Z890 Steel Legend WiFi no POST

Hi Smokey. A few things to check:

1. Make sure your RAM is fully seated in the slot/s, a new board's slots can be
quite a tight fit and if the RAM is not all the way seated it won't detect correctly.
2. Try a single stick in slot A2 and leave the system on for 10 - 15 minutes.
Sometimes RAM training can take a very long time on the first POST. It should be
fast after the first training has been completed.
3. Remove the CPU and check for bent pins in the socket and check for any debris,
dirt or grime on the CPU itself. When you reinstall it make sure your CPU
cooler pressure isn't too high. The cooler should be "snug" but not tight. Some
of the CPUs critical memory related pins are on the outer edge of the CPU so if
their is enough pressure to warp the CPU substrate (green PCB) these will not
make proper contact.
4. Follow these steps to perform a complete CMOS reset. 10 mins should
be enough time to leave the system without battery and power.

Let me know how it goes.

I doubt it, 16gb sticks are hardly high capacity for DDR5. Your CPU has been supported
by your board since BIOS 1.39, the earliest available on your product page. It
may be worth trying to use flashback to update to the latest BIOS again incase the
first attempt failed.

The entire Klevv website is down for maintenance so I can't even check for compatibility
with your board on the RAM's QVL. If you have other RAM available I rotate between the
different brands to rule out a compatibility issue or a bad kit. Sadly
fake/broken RAM is a thing these days, people buy it, swap out the heatsinks/stickers
with a broken kit and send it back for a refund. Lazy retailers put it back in
stock without checking and some unfortunate person ends up buying it.

It would help if you had another system to test the RAM in.

For now try the flashback again, make sure to follow the instructions from your
user manual exactly. If you are lucky it's just a bad flash (which is fortunately
no longer an issue since you have flashback).

All this is based on the assumption that this is a new build, if it isn't, please
let me know. A system suddenly failing after working previously requires an entirely
different troubleshooting approach.