PC shuts down unpredictably—cooling fans briefly activate before stopping completely.
PC shuts down unpredictably—cooling fans briefly activate before stopping completely.
Video link: https://imgur.com/a/IBwsiDo Case: Phanteks Eclipse P600s Motherboard
Product: Supermicro X11SCQ (https://www.supermicro.com/en/products/m...ard/x11scq)
Processor: Intel Core i9-9900K
Power supply: Seasonic GX-850
Memory: 32GB RAM
Graphics card: NVIDIA GeForce RTX 2080 Ti
System setup: Connected to a UPS, power is cut off during long inactivity.
I received the motherboard, processor, RAM, GPU, and a 600W PSU. I upgraded the PSU to the one listed above. Over the past year, my PC has run smoothly. Recently, when I powered it on, the power switch activated, fans spun briefly, then shut down. This cycle repeated until I turned off the PSU.
After reattaching the PSU cables and checking connections, it worked for a couple of days. Then I switched to the wall outlet, but the problem persisted. I disconnected all cables and components, cleaned them, and tested the PSU’s 24-pin connector and PCIe ports. Voltages were normal (3.3v, 12v, 5v).
I consulted Seasonic’s datasheet for pin configurations and replaced the generic 600W PSU with the one provided. The issue seems intermittent. BIOS is up-to-date, RAM, GPU, and other PCIe cards were reset or replaced. Running Cinebench showed no abnormal behavior.
No unusual odors, smoke, or burn marks were noticed. The case’s interior appeared intact, and the motherboard was secured properly with standoffs. The PC remained stable even when idle for months. No water damage or power supply issues were observed at home.
The problem might be related to the PSU itself, especially if it’s not delivering consistent voltage. I’m unsure what exactly is causing it unless the PSU fails. Please advise if further steps are needed.
You might need to return the item via RMA and check if a replacement is available. It appears your Seasonic is near the PSU category, which could mean it's uncommon. I'm not able to assist further, but someone else might have a better solution.
You're considering whether the problem might be with the power supply unit, even though the voltages looked normal. Once you decide whether to retry or skip it, you'll know the best path forward. I'm trying to avoid needing to purchase a new motherboard.
It's natural to question this since 12V reads as 11.8V without load. I imagine it should hover near 12V or just above it when unloaded, only dropping to 11.8V under stress. Still, it's not impossible the regulator keeps it steady at all times—voltage stability can differ significantly between power supplies based on their design.