[SOLVED] New computer crashes randomly, wont boot without cmos reset

[FaceChange]

Hello all, i just built my first pc -

spec:
intel i7-9700k
Asus z390e
2x16gb G.Skill TridentZ RGB
2TB 850 evo
MSI Gaming X Trio RTX 2080 Super
Corsair R850x
Corsair H100i pro
Windows 10 pro 64-bit
(All components new out of box)

-but am running into a problem within the first couple hours of use. I booted successfully, and everything was fine, but then comp suddenly randomly crashed while i was waiting for downloads and browsing the internet. I troubleshot all the hardware, trying booting with only cpu and 1 stick of ram, slowly adding components to see if any were bad, but each time the same thing happened:
all rgb lights up, and a few of the fans start spinning while some dont (usually do on normal boot), gpu fan runs at max speed. All the usb hubs have power as well. Monitor shows no signal from gpu port or mobo port.
Eventually i found resetting cmos gets comp to boot again.
After first time, comp ran fine for 3ish hrs then did the same thing again.
Any idea what the problem is?

 

[Lutfij]

Which version of the BIOS are you working with on your motherboard? Are you working with 1903 or 1909 or a previous iteration of Windows 10?

 

[FaceChange]

I dont know, computer will not even post now... All components are new so it cant be a bad part? I dont understand why it was working fine, but now even cmos reset wont do anything

 

[Ketchup79]

Did you CPU come with the heatsink and fan? I would recommend putting that on temporarily and taking the water cooler out of the equation.

If it still doesn't post - what DOES it do now?

 

[FaceChange]

Did not come with cpu heatsink+fan.
Right now it is turning on, fans and rgb, but no display

 

[Ketchup79]

Is the H100 pump running? Do you have a fan connected to the CPU fan header on the motherboard?

 

[FaceChange]

Ok i tore apart pc, and rebuilt it, got it to boot and all is good.
H100 pump is running, with pump connected to cpufan header.

Edit: just crashed about 10 min in, (screen froze, rgb lights stopped cycling and are stuck on one color) now the computer doesnt want to boot. When i try to power on the led lights on mobo that usually light up when posting dont light up. Also the gpu fan goes to max rpm, while the chassis fans stop spinning.

Since i'm managing to post and get into windows and even browse a little bit before everything freezes and i have to hard power off what is the issue? Maybe it's the h100i? I know the manuals for mobo and water cooler were saying contradicting things: h100i pro comes with a usb cable that plugs straight into a usb 2.0 hub on mobo and communicates with mobo all the pump info, so i dont plug in the pump to the aio_pump header, but the cpu fan header. The fans that go with the radiator plug straight into cables coming off of the pump. Im thinking the mobo is reading that the pump is working improperly or something?

 

[Ketchup79]

Could be a power supply problem. I was going repeat what I stated above and make sure a fan is connected to the CPU fan header, but that a miss there would usually cause the computer to not to boot at all, instead of booting up and then crashing.

It may be too late now, but check the pump, radiator, fans, and power supply and see if anything is extremely hot.

For next time: if you computer boots again, the first thing you will want to do is go into the BIOS and check your CPU temperature. While in the BIOS, and if your temps stay good, stay there and see if it makes it past the 10-minute mark.

 

[FaceChange]

Ok, i will try that next time

Before it last crashed, i was monitoring temps on afterburner and it never passed 31c as far as i recall. What are possible causes for computer to just freeze?