X399 Gaming MB w/ New 2990WX Pauses at C0, Reboots

Just bought a new ASRock Fatal1ty X399 Gaming motherboard and the new AMD Threadripper 2990WX CPU.  Installed 4 x CORSAIR 64GB 16X4 DDR4 2666 VLPXC16 memory modules.  When I power on the system I can see the Dr. Debug POST code display cycle through several values and eventually stop at C0.  The system will stay at that code for about 15 seconds and then reboot, repeating the cycle.  I've tried disconnecting the SATA drives, reducing the memory configuration to 2 X DIMMs (A2 & B2), and tried swapping the DIMMs into different configurations, but no joy.  Since I don't see the C0 POST code documented in the Quick Install Guide/User Manual.

I concur, you need bios p2.10 followed by p3.20

[URL=][/URL]Use the rear-I/o panel flash-back usb port with your 2.10 bios file re-named to 'creative.rom', and then with power supply on, push the flash-back button on the back panel at the very top for about 3 seconds. It should flash green for a few minutes while it is flashing the bios and then stop when complete. Try booting and if you can, then use Tools->instant flash to flash up to 3.20. If you can't boot, change the 'creative.rom' file to your 3.20 bios file, and flash-back again. Then hopefully you will be able to boot to uefi. You may be able to shortcut it by just initially doing a flash-back straight up to the 3.20 bios??

I think it also might be important to have that power connector connected as the TR uses a great deal of it and this could be a problem.

Edited by jbmerrill - 16 Aug 2018 at 3:46am

What others said is possible. However, I had this problem over and over again when I first set up my TR1950X build, and that had 2.0 preinstalled. It booted up fine at first, but when I changed memory settings in BIOS I started getting C0 boot loops. I did literally everything. In fact I literally bought a new motherboard and got AMD to replace my CPU but neither helped. Of course I also flashed every version of bios through the button on the back, cleared CMOS, tried every combination of RAM, reinstalled CPU like 10 times, unplugged every combination of devices and drives, etc. Finally I was about to give in and just buy a xeon or something but my friend, really experienced technical consultant, begged me to let him pick it up and tinker with it and at least try before I returned it all. But back at his house, it booted up fine on the first try, he didn't even open the case. I came over and we went through all the settings I originally set, since by now the CMOS was cleared, and could not reproduce the C0 boot loop issue. I thought my problem was fixed and thanked him but back at my house, I booted up and... C0 boot loop! Turns out I had only ever tried plugging it in to one outlet. And turns out that particular outlet was fucked up somehow, since when I plugged my phone in, the charging indicator would constantly turn off and on. It occurred to me I shouldn't have it directly in the wall anyway. So I plugged it and the monitor into a surge protector and plugged that into a different outlet and it has worked fine ever since. Moral of the story is sometimes the problem is right under your nose, and outside of the computer lol. But since you got the same post code maybe you are having the same issue.