PC Won't boot after power flicker

[micromashor]

Earlier tonight, we had the power flicker several times, and my PC is not on a UPS. The power flickers didn't seem to do anything at first. Later, my PC suddenly and immediately shut down with no warning (hard stop). I turned off the power, let it sit for about 10 minutes, then made 3 attempts to start it back up:

1. The monitors came on (but still black), stayed that way for about 20 seconds, and then another hard stop.
2. The system booted and was functioning normally, but I noticed the fans were running a lot higher than idle due to high CPU usage - when I tried to see what was causing the high CPU usage, I got another hard stop.
3. On any subsequent boot attempts, it did the same as the first attempt.

I began investigating and made a few more attempts to boot it, and the first time, the BOOT motherboard light was on, so I shut down and cleared CMOS, and on the next boot, the VGA motherboard light was on - nothing ever appeared on the monitor.

System info:

• Ubuntu 22.04 amd64
• Ryzen 7 2700x
• 32GB Corsair DDR4-3200
• MSI GTX 1660Ti
  • (2) 1080p monitors connected with HDMI and DP
• MSI B450 Tomahawk Max Motherboard
  • I don't recall ever updating the BIOS, but I built this PC in December 2019, so my memory's a little foggy.
• Corsair 1TB NVMe SSD
• EVGA 80+ 850W PSU

 

Software running at initial crash: Chrome, VSCode, Spotify, Discord

 

 

This system has been stable since my last modification when I added 2 more identical sticks to double RAM from 16 to 32 GB in June 2021.

 

Thanks in advance for any help or advice!

---
Edit: I have never done any overclocking beyond increasing the memory clock to the standard 3200MHz

[Josh B]

Try removing the CMOS battery, and removing the power cable from your PC & click your power button 10 or so times. Put the battery back in and turn your pc on.

[micromashor]

20 minutes ago, Josh B said:

Try removing the CMOS battery, and removing the power cable from your PC & click your power button 10 or so times. Put the battery back in and turn your pc on.

Just did that, didn't seem to have any effect

[micromashor]

Update: I have been able to get the PC to boot into the OS, but I am still experiencing random shutdowns.

Could the PSU be damaged as a result of the power fluctuations, causing it to shutdown when something draws a lot of power?

Would appreciate any thoughts on the matter.

[micromashor]

Replaced PSU, now it won't power on at all. Still powers up with the OG PSU. Ugh.

[micromashor]

PSU had a bent pin, fixed it and the system powered up but still hard stopped shortly after. I guess it's the motherboard then.

[Harmsway1283]

What kind of CpU cooler do you have?

[micromashor]

5 minutes ago, Harmsway1283 said:

What kind of CpU cooler do you have?

Cooler Master AIO with 240mm rad

[Harmsway1283]

9 minutes ago, micromashor said:

Cooler Master AIO with 240mm rad

Have you checked if the pump has stopped working? Your CPU could be overheating, causing these shutdowns.

[micromashor]

12 minutes ago, Harmsway1283 said:

Have you checked if the pump has stopped working? Your CPU could be overheating, causing these shutdowns.

Good idea - I'll check that once I get my replacement mobo installed (already halfway through the swap). Last time I was in the BIOS, it showed the pump operating at a normal RPM, but I have not checked it since this issue started.

[micromashor]

1 hour ago, Harmsway1283 said:

Have you checked if the pump has stopped working? Your CPU could be overheating, causing these shutdowns.

Just tested the water pump, and it's completely dead. I have a spare air cooler on hand, I'll install it and see if it fixes things.

[micromashor]

Yep - water pump was dead. Installed air cooler and it works. Thanks again @Harmsway1283!

[Harmsway1283]

5 hours ago, micromashor said:

Yep - water pump was dead. Installed air cooler and it works. Thanks again @Harmsway1283!

Cheers! Glad it’s not a bigger problem.