Need help before I send in ROG Maximus XI Extreme for RMA

[SK8]

I have a big issue with new build ROG Maximus XI Extreme 😕 Can never get Bios on screen

I took battery out / clear CMOS , checked all connections, Tried bios update with USB it sits at AC code when it boots up no error beeps no nothing m/b lights up but nothing ever on my screen for bios. We removed video card tried on board video , tried 4 different screens , made sure L2 is enabled. Tried 2 different video cards , Checked all seta cables swapped them out no joy, reseat ram removed ram left one stick in A2 slot no joy. And cant even get into bios with onboard video. Beautiful build thinking at this point its a bad MB maybe. Full specs below. Any ideas and if I forgot to list other things we tried sorry my brain is freaking out at this point as this is the most over the top build I have ever done btw all fans work and light up.
Case - Corsair Obsidian Series 1000D
CPU - Intel I9 - 9900K Processor
CPU Cooler - Hydro Series H150i Pro RGB 360mm Liquid CPU Cooler
Motherboard - ROG Maximus XI Extreme
RAM - DDR4 G.Skill Trident Z RGB 4266Mhz 32GB
Tested Latency 17-18-18-38
Video Card - ROG Strix OC 1080Ti
SSD's - Samsung 850 Pro X-Three-1TB
Power Supply - Corsair HX 1200i
Fans - Corsair ML120 Pro 120mm Premium x 16 (6 for CPU Cooler push pull)
Command Pro x 2
RGB Fan LED Hub x 3
Corsair LED Lighting Pro Expansion Kits x 2
Monitor - Samsung 49" CHG90 QLED Gaming Monitor 144Hrz 1ms

[Silent_Scone]

Remove the motherboard and test outside of the enclosure. Are you getting any video signal at all, what Q-CODE does the system hang on when turning on initially (not when trying to use USB Flashback)?

[SK8]

Thanks for the post Silent Scone@ASUS The code is always AC the mouse and keyboard never get any light to them. We did remove everything from the case same deal nothing on screen or keyboard or mouse. And yes we get a video signal from the screen just nothing ever shows on the screen. I am thinking its just a dead m/b out of the box after three days of testing. So I am sending it in. 😕