Troubleshooting a Dead GPU: My Gaming Rig’s Sudden Meltdown

I recently encountered a frustrating situation while gaming on my PC that has left me seeking advice from fellow tech enthusiasts. In the midst of an intense raid in World of Warcraft Classic, my computer suddenly shut down without warning. Now, I’m grappling with a non-responsive system and need help diagnosing what might be the cause.

System Specifications

To provide some context, here are my current specs:
– 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

I recently replaced my power supply unit (PSU) with a new 750W model, moving from an older 600W PSU that had been in use for over 6 years.

The Incident

During a challenging 40-man boss fight, my screen went black and I was completely unable to restart my system. Initially, I suspected the PSU. I checked the wall socket and confirmed that other devices continued to work, which ruled out a power issue on that end. After trying a different power cable for the PSU and determining it was indeed the culprit due to its age, I decided to upgrade to a new one.

After installing the new PSU, I first connected just the CPU and motherboard to see if the system would respond—much to my relief, the fans began spinning! However, once I reconnected everything and attempted to boot the PC again, there was still no response. I disconnected the GPU, returned to the minimal setup, and once again, the fans powered on, indicating some hope.

Diagnosing the Issue

I then placed an old GPU, the GT 9800, into my system, and to my surprise, the PC successfully booted up. This leads me to strongly suspect the RTX 2070 is the source of the problem. It’s puzzling that it malfunctioned so drastically, going from perfectly operational to seemingly blocking power to the entire system upon connection. While a motherboard issue crosses my mind, testing that could prove challenging.

Seeking Suggestions

I would greatly appreciate any suggestions for further debugging. In addition to this, I was using MSI Afterburner (not for overclocking, but