My PC shuts down after sitting idle for roughly an hour or two, even though it stays stable during gaming, benchmarks, FurMark, and memory tests. The system has a Ryzen 7 7800X3D, 32GB of DDR5-6000 CL38, a Sapphire Pulse RX 7900 XTX, an MSI B850 Gaming Plus WiFi motherboard, a Lian Li RS1000G power supply, and a DeepCool LS720/LM360 cooler.
The problem began after replacing my previous motherboard, memory, and 850W power supply. I monitored temperatures and voltages with HWiNFO64, including the final moments before shutdowns, but nothing unusual appeared. I also tried disabling C-states, changing power-supply idle settings, and various other suggested fixes.
The shutdowns stopped when I temporarily installed a 1050W Cougar GEX power supply, which makes the Lian Li unit seem suspicious. However, the shop tested the Lian Li and said it was working normally. They even tested it in my system while idle, but it did not shut down during their testing. After bringing it home, it ran for about two weeks before shutting down again, and then repeated the failure after only another hour of idle time.
Event Viewer reports Kernel-Power 41, but there is no obvious temperature or voltage error. I am planning to run the Cougar supply for several weeks to confirm whether the issue follows the Lian Li unit. Could this still be a power-supply problem, or should I investigate USB devices, motherboard power states, drivers, or another source of intermittent idle shutdowns?
4 Answers
Do not overlook USB hardware and its control software. A faulty USB controller, AIO USB connection, monitoring utility, or peripheral driver can cause crashes that only happen during low-power states. Temporarily disconnect nonessential USB devices and uninstall or disable motherboard, cooler, RGB, and hardware-monitoring utilities one at a time.
Check Windows settings and disable automatic restart after a system failure. That may let you see a blue-screen error instead of having the machine appear to simply power off. Also review Event Viewer immediately before the Kernel-Power entry, since the 41 event itself is usually just the aftermath.
Kernel-Power 41 only means Windows detected that the previous shutdown was not clean; it does not identify the failed component. Since the system stops shutting down with the Cougar supply, the Lian Li unit or its interaction with your system is still the strongest lead. Running the Cougar for a few weeks is a reasonable way to gather more evidence, especially since the problem is intermittent.
The fact that the shop could not reproduce it does not prove the supply is healthy. Intermittent failures can depend on room temperature, outlet conditions, cable seating, or how long the system remains idle. Document the exact time of every failure, keep the video and event logs, and ask the shop to test the unit in your complete system for an extended idle period rather than only checking whether the fan spins.
I already disabled automatic restart and will check whether a more useful error appears after the next shutdown.