My PC suddenly shuts down after I've been playing games for a while. I already replaced the power supply with a new 750W Bronze unit, but the problem still happens. The system has an Intel i7-8700, GTX 1080, 24GB of RAM, and an AIO cooler. CPU temperature stays around 60°C during use. I installed the new PSU with its own cables, and Event Viewer doesn't show anything obvious. What should I check next?
3 Answers
Look in Event Viewer under Windows Logs and System for entries immediately before the shutdown, but don’t be surprised if there’s no useful error. Sudden power cuts often only produce a generic unexpected-shutdown entry. Reseat the RAM and GPU, inspect the motherboard power connectors, and test the system with XMP disabled and default BIOS settings.
A complete instant power loss can still point to a protection circuit being triggered, even with a new 750W supply. Make sure the graphics card has properly seated power connectors and, if it uses multiple connectors, run separate PCIe cables from the PSU rather than daisy-chaining one cable. If possible, test with another known-good PSU from a reliable brand.
Since the CPU is only around 60°C, overheating probably isn’t the immediate cause. Monitor both CPU and GPU temperatures while gaming, and check whether the GPU hotspot or VRM temperatures are much higher than the normal GPU reading. Also test with a demanding GPU benchmark and a CPU-only stress test to see which load triggers the shutdown.

Event Viewer only shows the unexpected shutdown and nothing that explains what caused it. I’ll try the default BIOS settings and reseat the components.