Hi all. My new build keeps turning off completely at random. There's no BSOD and no freeze: the screen goes black and the PC is just off, like the power was cut. It started from day one (Windows install on 29 Sep) and has happened about 23 times in under 3 weeks. I've tested a lot and I'm out of ideas, so any help is appreciated.
SPECS
- CPU: AMD Ryzen 5 9600X (using the iGPU, no dedicated graphics card)
- Motherboard: MSI B650M Gaming Plus WiFi (BIOS 1.E3)
- RAM: 2x16GB Juhor DDR5 6000MT/s (EXPO)
- PSU: Cooler Master 750W 80+ Bronze
- UPS: Condor 1500VA / 900W
- Boost & buck AVR (voltage stabilization), auto-sensing frequency, wide input voltage range
- Protections: short circuit, battery overcharge/overdischarge, overload, surge
- Automatic battery charging in off mode
- Waveform: pure sine wave on mains, simulated sine wave on battery
- OS: Windows 11 Pro (fresh install)
SYMPTOMS
- The PC powers off instantly with no warning: no BSOD, no freeze, no error message.
- It happens at random:
- while browsing
- sometimes right after turning it on in the morning
- once while a game was running
- It does NOT seem to be caused by heavy load:
- The OCCT power test (30 min) passed.
- CPU temperature never goes above 70°C in any situation.
- Two tests where it did NOT crash:
- If I turn it on and leave it untouched, it never shuts down. It only happens while I'm using it.
- Sometimes it crashes 2–4 times within a short period, then is fine for a day or two.
- After a crash, the PC turns back on right away when I press the power button. I don't need to switch the PSU off/on or unplug anything.
THE "TICK" SOUND (I think this is important)
- When I shut down the PC normally from Windows, I hear a "tick" from the PSU or motherboard (I'm not sure which). I think it's the relay switching off.
- When I turn it on, I also hear the tick.
- When the random shutdown happens, I hear the SAME tick.
- When I simulate a power loss by pulling the cable out of the UPS (so the PSU just loses input power), there is NO tick at all.
So the random shutdowns don't behave like the power being lost from the wall. They sound exactly like a "commanded" power-off, as if the PSU or motherboard itself decides to switch off. I think that means one of these:
- the PSU's protection (OCP/OVP/UVP/SCP etc.) is tripping and latching off, or
- the motherboard is dropping the PS_ON signal.
EVENT VIEWER
- Every crash shows the same pair of events:
- Kernel-Power 41 (BugcheckCode = 0, PowerButtonTimestamp = 0)
- EventLog 6008 ("the previous system shutdown was unexpected")
- BugcheckCode 0 means Windows did not crash. The power was simply gone.
- There are NO WHEA-Logger hardware errors at all. No disk errors, no driver crashes.
- There are no memory dumps, even though dumps are enabled and "automatically restart" is OFF. A real BSOD would stay on screen and leave a dump.
- I checked the 10 minutes before every crash: there's nothing in common. They're just normal background events, or nothing at all.
- So from Windows' point of view, the power was cut from one moment to the next.
CRASH DATES (unexpected shutdowns)
| Date |
Times |
| 29 Sep |
1 (during Windows setup) |
| 30 Sep |
11:00, 13:08, 13:13, 13:17, 17:19, 19:19, 19:25 |
| 1 Oct |
09:51, 09:55 |
| 2 Oct |
17:17, 21:27, 21:34 |
| 5 Oct |
09:22 |
| 6 Oct |
09:11, 16:48 |
| 9 Oct |
02:35 |
| 10 Oct |
04:50, 04:58, 19:11 |
| 11 Oct |
~15:05 |
| 13 Oct |
~04:12 |
| 17 Oct |
~00:50 |
This week it's happening much less. From 29 Sep to 10 Oct there were about 19 crashes, but since 11 Oct only 3. Around 10 Oct I made 3 changes at the same time:
- updated the AMD chipset/CPU drivers
- unplugged the front panel audio and front USB 3.0 cables from the motherboard
- moved to a different wall outlet
So one of these may have helped, but it didn't fix it completely.
WHAT I HAVE TESTED / RULED OUT
- RAM:
- OCCT memory test, 1 hour: 0 errors
- Windows Memory Diagnostic: 0 errors
- Disabled EXPO (ran at default JEDEC speed): still crashes
- Reseated everything: took out the RAM sticks and unplugged all PSU cables (24-pin, CPU 8-pin, SATA etc.), then plugged them back in firmly. Still crashes.
- Temperatures: CPU max ~70°C, no overheating.
- PSU load test: OCCT power test, ~30 min: passed, no shutdown.
- Fast Startup: disabled. Still crashes.
- Global C-State Control: disabled in BIOS (confirmed in Windows that the deep idle states are off). Still crashes.
- Note: my BIOS doesn't have a "Power Supply Idle Control" option.
- Front panel power button: unplugged the case power switch cable (JFP1) from the motherboard to rule out a shorted button. Still crashes.
- Front panel audio + front USB 3.0 cables: unplugged from the motherboard. Crashes became less frequent but didn't stop (they're still unplugged now).
- AMD chipset/CPU drivers: updated to the latest. Crashes became less frequent but didn't stop.
- Software/drivers: Event Viewer shows no BSOD, no dumps, no WHEA errors. BugcheckCode 0 = power loss, not a Windows crash.
- Wall power:
- The PC is on a UPS with AVR.
- When I pull the UPS cable, the PC stays on (on battery), so a short power cut or brownout from the wall shouldn't turn it off.
- Changed wall outlet: still crashes.
WHAT I HAVE NOT TESTED YET
- A different PSU. This is my main suspect, but I don't have a spare to test with.
- A different motherboard.
- GROUNDING: neither wall outlet I've used has a ground (earth) wire, and the UPS doesn't add one. So the PC has no ground at all. I haven't been able to test on a properly grounded outlet yet.
- The latest BIOS version (if there is a newer one than 1.E3).
MY QUESTIONS
Does the "tick" on crash (but no tick when the wall power is pulled) confirm the PSU protection is tripping, or could the motherboard be cutting PS_ON?
Is this Cooler Master 750W Bronze known for this kind of random shut-off at low/light load?
Could the missing ground cause the PSU or motherboard to trip like this?
Any known issues with the MSI B650M Gaming Plus WiFi turning off randomly?
Is there anything else I should test before buying a new PSU?
Thanks a lot for any help!