Strange PC Problem: randomly kind of turning off and on again

Understanding and Troubleshooting Intermittent PC Restart Issues: A Comprehensive Guide

Introduction

Experiencing sudden and random shutdowns and restarts can be both perplexing and disruptive. If your high-performance PC is intermittently powering off and rebooting without clear cause, it’s essential to approach the problem systematically. This article explores common causes, diagnostic steps, and potential solutions to help identify and resolve such hardware or software issues effectively.

System Overview

Before diving into troubleshooting, understanding your hardware configuration provides valuable context. Here is a typical high-end workstation setup:

• Memory (RAM): 64 GB (usable approximately 63.7 GB)
• Solid State Drive (SSD): 932 GB Samsung SSD 860 EVO
• Graphics Card (GPU): NVIDIA GeForce RTX 2080 Ti (11 GB)
• Operating System: Windows 10 Pro
• Motherboard: ASUS PRIME X299-DELUXE II
• Processor: Intel Core i9-9940X (14 cores, 28 threads)
• BIOS: American Megatrends Inc., version 0404 (dated November 5, 2018)
• Power Management Mode: UEFI BIOS

Identifying the Problem

The issue manifests as the PC randomly shutting down, then restarting. Post-restart, the display may show no signal, and GPU fans often run at maximum speed. This behavior occurs unpredictably—sometimes within minutes, other times after hours—and can happen during mundane tasks like browsing or intensive activities such as gaming.

Key symptoms include:

• No visual output immediately after reboot
• GPU fan spinning at maximum speed
• Requirement to force shut down and restart
• Inconsistent occurrence intervals

Initial Diagnostic Steps

1. Monitor System Temperatures and Voltages

Use tools like HWMonitor or HWInfo to monitor real-time temperature and voltage readings. During stress tests like FurMark or Prime95, ensure components stay within safe operating ranges.

1. Stress Testing Hardware Components

2. GPU: Run FurMark to verify GPU stability. If the GPU runs at high load without issues, the GPU may not be the culprit.

3. RAM: Use MemTest86 to check for memory errors. Multiple passes and extended testing can reveal faulty RAM modules.

4. Review System Logs

Check Windows Reliability Monitor and Event Viewer for warning or error logs correlated with the times of crashes. While sometimes these logs are unhelp