Problems with Strix B450-I

[SlowMixit]

I have following problem with my new ITX pc build.

 

Random shutdowns, all screens go blank and go to standby mode, all fans go to max rpm.

Happening randomly, sometimes right after booting Windows, sometimes maybe 6-12 hours later.

Temperatures are in check CPU temperature max. 70'c on Prime95 load overclocked to 4.1Ghz@1.40v (the issue is there with stock too), mainboard sensors say everything is between 30-45'c, i have got fan blowing air to VRM so it should be also in check.

 

What i have tested :

Different PSU's and its happening with bowth (EVGA G2 1000W and Silverstone SFX 650 Gold)

Different RAM (16Gb Corsair DDR4 3600 CL18 B-die kit and 8Gb G.Skill DDR4 3200 CL14 B-die kit)

Only things i cannot test right now is different CPU and GPU but as GPU works perfectly with friends pc from who i purchased it so i dont think its GPU.

 

Anyone have any ideas? Bios is up to date so i can only think that i got faulty mainboard.

 

Specs :

AMD Ryzen 2600 (Stock, 3.8Ghz or 4Ghz or 4.1Ghz does not matter the issue is there regardless).

Asus Strix B450-I 

16Gb Corsair DDR4 3600 CL18 kit (3466@CL14, Stock or 3600@CL18 does not matter the issue is there regardless)

Gigabyte RTX 2060 OC 6Gb

Corsair H115i RGB Platinum AIO
Win10 1903 64Bit

[GoldenLag]

lower memmory speed to 3200mhz and see if its memmory instability that is triggering it. 

 

other than that it could be VRM powerthrottling, though that would be sort of wierd. 

[SlowMixit]

I have tried stock non-xmp settings that board boots after resetting cmos (2133Mhz) and it does happen with those settings too.

 

Memory it self passes 8+hours test of HCI MemTest (13Gb used) and 8+hours of Karhu RAMTest with 3466@CL14 1.45v, memory also passed same test with 3600@CL15 1.45v.

It does not work 3200@CL14 either on this or another memory kit.