Everything default.. thing is if i let it idle on the BIOS for 10 mins or so then boot up, pc will work fine for a couple of days - until a reboot or shutdown. Also, if I don't install VGA drivers, PC will boot up without crashing.
I've had similar issues. When I first built this PC, with RAM speeds and volts all set at Auto/stock, the system was rock solid. However if I simply enable XMP, the system will not POST, I get red CPU debug LED. In fact, at auto volts, my system doesn't POST above about 2800mhz RAM speeds.
I followed Ryzen calculator for some RAM / volt settings for 3600mhz, for me it was 0.9v VDDP/VDDG and 1.025v SOC. When I first tried these settings with 3600mhz for my RAM speeds, it POSTed and loaded Windows first time no problem and I though I had it sussed. However after about a week of running the system I was seeing weird, random crashes. For example I would finish playing a game, quitting to desktop. I would leave the machine and come back to a black screen, but machine powered on. I would need to power off and turn it back on. Or I would close web browser and system would lock up, again needing power off and restart.
I thought at this point I had issues with my Windows install. So I set everything back to stock, re-installed Windows then restored my overclock settings in BIOS. Issues continued, mainly when the system was going from load to idle. This time I set BIOS to stock, booted back into Windows and checked my stock volts in Ryzen master. The voltages were around the same or only marginally lower than the overide voltages I had set based off Ryzen calculator.
After this I tried going step by step with starting at 1.0v VDDP / VDDG / 1.1v SOC and testing. At these voltages it was perfectly stable, after changing each voltage separately I've gotten to the point I'm happy is the minimum volts on my machine to solve the instabilities/crashing.
1.0v VDDG / 0.975v VDDP / 1.065v SOC roughly.
I swear a lot of issues for the 5700XT are down to the Ryzen CPUs, I'm not sure of the technical reasons but it seems like all my issues were down to the volts with the memory controller / infinity fabric volts on the CPU, not sure how much the motherboard impacts this?