I received a new custom-built PC today, but it immediately shuts off whenever I launch a game—even before entering a match. In Arena Breakout, the screen goes black and the system powers down, while the RGB lighting remains frozen until I physically disconnect the power cable.
The same thing happens within one or two seconds of starting the OCCT Power test. This makes me wonder whether the power supply is faulty or whether 1000W is insufficient for the system, although I would have expected the builder to catch a power issue during testing.
The main components are a Ryzen 9 9950X3D, Gigabyte X870 Aorus Elite WiFi7 Ice motherboard, 64GB DDR5-6000 memory, RTX 5090, Samsung 9100 Pro 2TB PCIe 5.0 SSD, Corsair 360mm liquid cooler, and a Corsair 1000W RMe ATX 3.1 Gold-rated modular PSU. What should I check, and should I return it to the system builder rather than troubleshooting it myself?
3 Answers
Check CPU and GPU temperatures at idle and during a load test. If temperatures climb instantly, the system could be triggering thermal protection. Also verify that any protective film was removed from the cooler cold plate and that the pump is running. The 1000W supply may be adequate in some configurations, so temperatures and power behavior are worth checking first.
A 1000W PSU looks questionable for a system pairing an RTX 5090 with a top-end Ryzen 9, especially if both can experience short power spikes. It may be shutting down because the supply is reaching its protection limit, although a defective unit is also possible. The builder should have validated the configuration and should provide a properly rated replacement if necessary.
Contact the builder before changing parts or repeatedly stress-testing it. Since the machine arrived faulty and is still covered by the warranty or return policy, they should diagnose whether the PSU, cabling, motherboard, cooling, or another component is defective and arrange a repair or replacement.
That is what surprised me too—the builder's configurator recommended this power supply, and the completed system apparently passed their checks. I will have them investigate it rather than buying a replacement myself.