Diagnosing a PC Crash: Is My GPU at Fault?

I recently encountered a frustrating situation with my gaming PC while immersed in a 40-player raid in World of Warcraft Classic. Just as the boss fight intensified, my screen went black, and my system completely shut down. After multiple attempts to power it back on, there was no response at all. Initially, I suspected the power supply unit (PSU), but I’m now leaning towards a potential issue with the graphics card (GPU). I would appreciate any insights on diagnosing this issue.

Current Specifications

Here’s a quick rundown of my system specs:
– CPU: Ryzen 7 3700X (recently upgraded, used)
– GPU: RTX 2070 (Inno3D TwinX2, approximately 1.5 years old)
– Motherboard: MSI B450 Pro Max (about 2 years old)
– RAM: 32GB DDR4

The original PSU was 600W, but I’ve upgraded to a 750W unit due to my concerns about power delivery.

The Incident

While engaged in an intense gaming session, my system unexpectedly powered down. After ensuring that the wall socket was functional (other devices were operating normally), I swapped out the power cable, but there was still no response. Given that my previous PSU was over six years old, I decided to replace it with a new 750W unit.

After connecting just the CPU and motherboard, I was relieved to see the fans spin up, suggesting that the new PSU was operational. I proceeded to connect the remaining components, but when I attempted to boot the PC, there was still no sign of life. Disconnecting the GPU yielded no results; however, unplugging the PSU from the wall and reconnecting it allowed the fans to start once more.

To further isolate the issue, I installed an old GT 9800 GPU that I had lying around, and miraculously, my PC booted up without a hitch. This strongly indicates that my RTX 2070 may be the culprit. It’s odd to think that a GPU could transition from functioning well to effectively incapacitating the entire system. While I’m still holding out hope that the motherboard is to blame, I recognize that testing that hypothesis is more complicated.