Question Computer keeps crashing (or freezing?) ever since I tried to update graphics card

[gm66]

A little while back, I got my hands on an MSI RTX 2070 Armor and tried upgrading to it immediately. However, soon after installing it, my computer would crash every so often, especially if I put strain on it like using VR. So I took the card out, and put the old one back in, but still, I would get crashes randomly, though not as often. I thought I may have damaged the power supply, so I upgraded it, but no change. Recently, it's gotten really bad, and I can hardly go an hour without my computer just freezing up (screen and audio stop working, peripherals shut off). I'm worried I may have caused damage to some other components of the computer, hence why I'm asking for support.

My current graphics card (the one I tried to upgrade from) is an AMD Radeon RX 480, and the rest of my build is as follows:
CPU: i7-8700k
CPU Cooler: Dark Rock 4
RAM: 32 GB Corsair
Previous PSU: EVGA 500W Bronze 80+
Current PSU: EVGA SuperNOVA 650 G+
Case: NZXT S340 Mid-Tower

I honestly don't know what the problem could be. At first I thought it was the graphics card overheating, then I thought it was my PSU, but my fixes seem to shoot down those problems. Also, as an aside as I'm not sure if it's relevant, on startup one of the case fans makes a buzzing noise and seems to "flicker" a little bit, but the noise goes away after 30 seconds to a minute.

I would greatly appreciate any help I can get. I have an online class coming up and I need my computer to be in fully working condition by then. So thank you very much in advance! Let me know if I need to provide any more details.

 

[Ralston18]

What drives are installed in your system: how much power do those drives demand?

Check in Reliability History/Manager and Event Viewer for error codes and warnings - something may be being captured there.

Use Task Manager and Resource Monitor to observe system performance. They may likewise reveal some overall system issue - a bottleneck perhaps that leads to the crashes.

And do doublecheck the hardware requirements necessary to support your VR software/games. Your system may meet the minimum or recommended requirements but even if so that does not meet that the performance will be as expected.