Could not identify the reason for the unexpected shutdown during startup.
Could not identify the reason for the unexpected shutdown during startup.
Hello everyone, I’m operating a custom-built PC and have faced a challenging problem: under heavy usage, the system crashes abruptly without notice—often during intense gameplay sessions like Expedition 33. What I’ve Attempted So Far: I assumed the recently installed GPU might be faulty, so I replaced it with an RX 7800 XT from another machine, which functioned properly. I also updated all drivers and the motherboard BIOS to the latest versions. I kept the games fully updated and monitored temperatures; CPU hit around 80°C while GPU stayed near 74°C. I reapplied thermal paste on the CPU and switched coolers from a liquid cooler to an Arctic Freezer 34 eSports DUO air cooler. Temperatures improved, but shutdowns persisted. I upgraded the power supply to a Corsair RM850x and used dedicated PCIe leads for the GPU. The issue continued. I checked the CPU in another system with a Ryzen 5 5600X and found no shutdown problems there. RAM tests showed two Corsair Vengeance sticks at 16GB DDR4-3600 MHz, installed in slots A2 and B2; Memtest confirmed no errors. After swapping or verifying every major part, I’m still stuck. Any experience with similar cases would be appreciated, or what else should I investigate?
Build Details: CPU – AMD Ryzen 5 5600X
Cooler – Arctic Freezer 34 eSports DUO (air)
GPU – Radeon RX 7800 XT
Memory – 2 × 16GB Corsair Vengeance DDR4-3600MHz (32GB total)
Motherboard – MSI MAG B550 Tomahawk (BIOS 7C91vAI latest)
PSU – Corsair RM850x (new)
Storage – Drive 1: 2TB Samsung 980 Pro PCIe 4.0 NVMe (game library)
Drive 2: 1TB Samsung 970 EVO Plus NVMe (extra games)
Drives 3 & 4: 500GB Samsung EVO SSDs
OS – Windows 11 on Drive 3 (EVO SSD)
I own an RM650x, but I replaced it with the newer model since the specifications didn’t match the new GPU. I could revert it, but there were shutdown issues with that PSU before.
Welcome to the discussion boards! Power problems are usually the main culprit. Switching to a solid PSU seems unlikely now, so I think wall power might be the issue. If you're in an area with inconsistent electricity or an older structure, consider investing in a UPS (CyberPower 1500VA LCD is my go-to). When budget is limited, relocating your setup to another location could help. A simpler approach is testing a different circuit in your home—kitchen appliances often have separate circuits, though this is more common in newer homes. Before proceeding, verify that a full load shutdown works. Running Prime95 and Furmark together should stress the system to its limit; if it fails, try elsewhere.
Thanks for the friendly introduction and creative approach. We completed all the electrical work about two years ago and have managed to run another PC on the same circuit without any problems. During a recent LAN party, I was connected to the downstairs circuit in the living room and still faced shutdowns—no power instability observed. I’m planning to try your recommended tests using Prime95 and Furmark together to see if they can trigger a shutdown. A UPS might be worth considering, but I suspect the issue isn’t with the power input. Appreciate your advice!
If you've got the cash for it, it's always a good idea. If you're out of 200$ upgrades, the next one should be a UPS because it (to a degree) protects everything downstream of it. If the UPS doesn't fix it, I guess it *could* be the mobo. Or, (and this is a REMOTE) chance, there is a tiny possibility that somehow the power button is getting activated. But that would be a WILD edge case. Like, the heat of the case causes expansion of some component and is activating the button. Or the front panel connector wires are the perfect length to act as an antenna for the EMI caused by the fans at a specific speed. But again, those are bugnuts scenarios and should have been present since the initial build.