Sudden power off and restart since changing pc case/fans.

Addressing Sudden Power Losses Following PC Case and Fan Upgrade: Troubleshooting and Recommendations

Upgrading your PC’s case and cooling system can enhance thermal performance and aesthetics; however, such modifications sometimes introduce unforeseen issues. Recently, a user reported experiencing sudden power-offs and automatic restarts following a case and fan upgrade. In this article, we will explore potential causes, troubleshooting steps, and best practices to resolve these common challenges.

System Overview

The user’s build comprises:

Graphics Card: AMD Radeon RX 7900 XT
Processor: Intel Core i7-14700K
Motherboard: TUF GAMING B760-PLUS WIFI
RAM: G.Skill Trident Z5 RGB, 64GB (2x32GB)
Power Supply: Corsair HX850i
CPU Cooler: Corsair H100i ELITE Capellix XT AIO
Case: Corsair 3500X Mid Tower

Symptoms

Post-upgrade, the system functions normally during idle or regular tasks. However, during intensive activities such as gaming or GPU stress testing, the PC abruptly powers off and restarts. The user has verified:

Proper PSU connections and reseated all components
No errors in Memtest86 for RAM
Occasional restarts during GPU stress testing (Kombustor)

Potential Causes and Troubleshooting Steps

Insufficient or Misconnected Power Delivery

Despite checking connections, ensure all power cables, especially GPU 8-pin or 6+2 pin connectors and CPU power connectors, are securely attached. Sometimes, rearranging or replacing cables can help.

Thermal or Cooling Issues

Though temperatures appear acceptable during regular use, increased load might cause thermal throttling or shutdowns if cooling isn’t adequate. Verify that the CPU cooler is properly mounted and that airflow within the new case is optimized. Use monitoring software to check real-time temperatures during stress tests.

Electrical or Grounding Problems

Replacing the case could introduce grounding issues. Confirm that the motherboard is properly grounded and that the case is not causing short circuits. Inspect for any loose screws or residues that could cause shorts.

Power Supply Capacity and Stability

The Corsair HX850i is a high-quality PSU; however, ensure it is functioning correctly. Consider testing with a different power supply, if available, to rule out PSU-related problems.