PC keeps restarting under load – tried different GPU and PSU, still no fix

Troubleshooting Guide: Resolving Random PC Restarts During Load

Experiencing unexpected restarts during gaming or other intensive tasks can be a frustrating issue for PC users. If your computer reboots spontaneously under load—whether during gameplay, video streaming, or even simple activities—it’s essential to methodically identify and address potential causes. Here’s a comprehensive overview based on a typical scenario, along with recommended troubleshooting steps.

Common Symptoms

Random system reboots under load
No Blue Screen of Death (BSOD)
Temperatures remain within safe limits (below 70°C)
No significant system usage spikes observed during restarts
Testing different hardware components yields the same issue

Hardware Environment Overview

Processor: Intel Core i7-8700
Graphics Cards: RTX 2060 6GB (also tested with GTX 1050 Ti with no change)
Power Supply Unit (PSU): Thermaltake RGB 650W (swapped with an alternative PSU to rule out power issues)

Initial Observations and Troubleshooting

Temperature and Usage Monitoring
Temperatures are within normal ranges, indicating thermal throttling or overheating is unlikely the cause. Use tools such as HWMonitor, HWInfo, or MSI Afterburner to observe real-time metrics.
Power Supply Check
Despite swapping the PSU, the issue persists. A consistent problem across different power supplies suggests that the PSU might not be the root cause.
Hardware Component Testing
Testing with different GPUs (RTX 2060 and GTX 1050 Ti) pointing to the same systemic issue indicates the problem isn’t solely graphics-related.

Potential Causes and Solutions

1. Power Delivery and Stability

Even with swap testing, faulty or inadequate power delivery can cause system reboots under load. Verify:

Ensure all power connectors are securely connected.
Consider testing with a higher wattage or higher quality PSU, preferably one with an 80 PLUS Gold or Platinum certification.
Use a dedicated power supply testing tool or method to validate stability.

2. Memory Stability

RAM issues are a common culprit: