PC suddenly shuts down following freezing up, having a hard time figuring out why

Understanding and Troubleshooting Unexpected PC Shutdowns During Gaming: A Guide

Encountering sudden system shutdowns can be both frustrating and perplexing, especially when they occur during specific applications like gaming. If your PC is freezing into a nearly unresponsive state before shutting down without a blue screen, and you’ve already exhausted common troubleshooting steps, it may be time to delve deeper into hardware diagnostics and system configurations. Here’s a comprehensive approach to diagnosing and resolving such issues.

Symptoms Overview

System experiences freezing for approximately 0.5 seconds, resulting in a slideshow-like display with audio driver hanging.
After about 20 seconds of freeze, the PC shuts down abruptly without generating a Blue Screen of Death.
The shutdown pattern appears synchronized with playing a specific game, Apex Legends, typically after around 10 minutes of gameplay.
Booting into Windows becomes sluggish, eventually failing until the power supply is cycled off and on.
No indication of errors in Windows Event Viewer other than an unexpected shutdown event; no minidump files are present.

Initial Troubleshooting Steps Attempted

Driver rollbacks using Display Driver Uninstaller (DDU) with multiple older versions.
Reinstallation of motherboard chipset drivers.
Memtest86 executed with no apparent memory issues.
Power Supply Unit (PSU) has been tested via RMA, cables replaced and reseated.
GPU reseated and checked physically.
Hardware monitoring with HWinfo shows no obvious anomalies.
System fails to generate minidump files, limiting crash analysis.

Potential Causes and Diagnostic Strategies

Hardware Instability or Overheating
GPU and CPU Temperatures: Monitor temperatures during gameplay using reliable tools like HWinfo or MSI Afterburner. Overheating can cause thermal shutdowns.
Power Supply Reliability: Despite having tested your PSU, consider testing with a different, known-good PSU if possible. Power fluctuations or insufficient power delivery can cause shutdowns during graphics-intensive tasks.
Other Components: Check for loose cables, especially power connections to GPU and motherboard. Ensure all connectors are firmly seated.
Graphics Card Issues
Driver Conflicts or Hardware Defects: Continue testing with different GPU driver versions, including the latest official releases and stable older variants.
Stress Testing: Use tools like FurMark or 3DMark to stress the GPU in a controlled environment, observing for crashes or shutdowns.
Physical Inspection: Check for signs