What Power Supply (Make & Model & Age) are you using?
Do you have the 24-Pin Motherboard and 8-Pin ESP/CPU Cable Plugged in and Locked?
What are you using to Cool the CPU?
You Must Have at least One Memory Stick installed in Slot 1 to Post.
And Should have a Graphics Card Installed to Complete a Full Post or it will stop at D7.
A Full Post can also take up to 4 restarts of the computer the First Time it is turned on or after Pressing the Small Red Button or Updating the Bios.

I have 1 Corsair 1200i Power Supply and 3 EVGA 1300 G2 Power Supplies that would Not Power on and Post on 3 of my X299 Dark Motherboards and 1 X299 FTW Motherboard. (Not a Beep)
But all 4 would Power Supplies still work fine on my EVGA X79 Motherboards and 1 ASUS X79 Motherboard and work just fine.
But they are 3, 4,  and the Corsair is 5 years old.
ATM 2 of the 1300 G2 are powering my X99 FTW K Motherboard running 2 RTX Graphics Cards View System Not a single issue.
My ASUS X79 is running the 3rd 1300 G2 along with a single GTX 1080 Ti Hybrid Card and Not a Single issue as well.
My 4th 1300 G2 is installed in my X99 Classified Motherboard but I never removed it to test on the X299 Motherboards. View System
 
Why will they not work, who knows. But I moved on and bought new Power Supplies and all is running Great.
 

Pull the MB - put in on a nonconductive surface (if the box is dry that works)
 
1 stick RAM, CPU & CPU cooler .... use Start button on MB ... what happens
 
Are All power cords the ones that came with your PSU ?
 
When seating the cords -- push on the Wires & not the plastic socket -- sometimes the wire will push back into that plastic socket, just enough to cause issues

Did your PSU come with the "Tester Cap" for the 24-pin power cord ?
 
Are you positive the MB battery is installed the correct way -- happens
 
Got to ask -- Test the wall outlet with a lamp or something
 
If PSU has a switch on the back --- Cycle that switch

Lillehamer
Thanks again, i have a multimeter but no Tester cap for that 24 pin power cord, Mb Batteri is monted the right way, i know, outlet is okay, cycke the switch foe sewel times, no post, i can se another Evga member i this thread, have tryed no post code, no beep code whit 2 difrents powersuply, that is strenges, i have ask what powersuply he use now whit luck, but he dident  repley yett. So maby somthing abaut this powersuply, or defektive motherboard????

If me I am using the SuperNOVA 1600 G2, SuperNOVA 1600 T2, SuperNOVA 1200 P2, SuperNOVA 850 G3

Lillehamer
And this you dont have any problems whit EVGA 299x Dark Motherboard???????
But like you said thats strenge... Hummmm. Thanks.
And now i have used my multimeter to test the cord 8 pin, no problem 12.10 volts on all.

Correct
Use a Friends Power Supply to test with, make sure you only use the Cable that Come With the Power Supply.
Do not mix Cables from different Power Supplies.
 

Lillehamer
I will try, i had another one, but no luck whit this one too.

What was the Make and Model plus the Age?
Do Not Mix Up the Cables...

Keep us Posted

bcavnaugh
Keep us Posted

I will do, this i importen.

There is 2 conectors, from direkly the case.
 

Model number is CMPSU-1000HX, this is the only it say on the top at powersuply, hope this is okay???
 

https://www.corsair.com/us/en/Categories/Products/Power-Supply-Units/Professional-Series%E2%84%A2-HX1000%C2%A0%E2%80%93-80%C2%A0PLUS%C2%AE-Certified-Modular-Power-Supply/p/CMPSU-1000HX
 

The Corsair HX1000W features six PCIexpress connectors, both 6-pin and 8-pin compatible, to power multiple high-end graphics cards and two EPS12V connectors for dual CPU configurations. The truly independent dual transformer, dual rail design allow for optimum load balancing resulting in greater performance and stability. Industrial-grade 105°C primary, secondary and solid state capacitors provide up to four times the lifespan of traditional components.

 
Yes - 2 x EPS
 
Perhaps the X299 Dark does no play well with dual rail power supplies - inconsistent voltage levels across the 2 connectors
 
That video you linked is 11 years old - old tech might not be up to the task

Okay, now there is new comming up here, there is NOT a problem whit my PSU (CorsairHX1000) woork perfectly, tryed on a Corsair 750 Watt too, woork perfekt on the board, i have tryed 2 defrents board EVGA 299 x, and it works great, but but but the thing was (DEAD CPU) 7940x, damm it is allways me. that get into this strenge things, a dead CPU dammmm, but now LED Debug led light up on both MB, nothing to do whit Corsair PSU, woork like a champ.