Troubleshooting a Mysterious PC Shutdown: Diagnosing GPU or PSU Issues

The world of gaming can often lead to unexpected technical challenges, and recently, I faced a perplexing situation when my PC unexpectedly died mid-game. While battling away in a 40-man raid during World of Warcraft Classic, my system suddenly fell silent, leaving me puzzled and eager to pinpoint the issue. Here’s a rundown of my experience and what I’ve discovered along the way.

The Setup

To give you some context, here are the specifications of my gaming rig:

• CPU: Ryzen 7 3700X (recently upgraded, second-hand)
• GPU: RTX 2070 (Inno3D TwinX2, approximately 1.5 years old)
• Motherboard: MSI B450 Pro Max (2 years old)
• RAM: 32GB DDR4
• Power Supply: Recently upgraded from a 600W to a 750W model

The Incident

While enjoying a relatively low-demand game like WoW Classic, my screen suddenly went black during an intense boss fight. Initially, I inspected the power socket, confirming other devices remained functional. Suspecting an issue with the power supply, which was over six years old, I decided to invest in a new 750W PSU.

After installing the new unit, I connected the CPU and motherboard first to see if I would get any response. The fans powered on, which was a good sign. However, once I connected everything and attempted to power on the PC, it displayed no signs of life—neither sound nor light.

Out of desperation, I disconnected the GPU and tried powering on the system with only the CPU and motherboard. Again, no response until I completely unplugged the PSU from the wall and then plugged it back in, which made the fans spin up once more.

Temporary Solution

To keep things moving forward, I rummaged through my old components and connected a GT 9800 GPU—the only spare I had on hand. Miraculously, this setup allowed my PC to boot up normally, leading me to suspect that my RTX 2070 was the culprit.

It felt strange that a GPU could fail so drastically, rendering the entire system inoperative with just its mere connection. My hope began to wane, and I worried that it might be a motherboard problem, but diagnosing that could prove more complex.

Seeking Advice

At this stage,