[SOLVED] Random power offs, reboots, and failure to turn on...

May 16, 2019
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My system:

Asus ROG Strix Z390-I Gaming MOBO
Intel i5-9600k
EVGA GeForce GTX 1080 FTW Hybrid
TEAM T-Force Nighthawk RGB RAM 2x8Gb
Western Digital 500GB Nvme
Cooler Master Masterliquid ML240R RGB CPU cooler
Corsair RM750x 750W power supply
NZXT h200 mini-ITX case

My issue is this:
Bizarre instability in BIOS and Windows. The computer just randomly powers off without a blue screen and then attempts to reboot, sometimes successfully, sometimes not. When the answer is no, the computer is unresponsive for some time (no change when pressing the power button) before randomly powering back on. This is a brand new pc build that I'm using exclusively for gaming. I should note that these power offs ironically happen most often when the system is left idle. To me this seems like a power supply issue and I've ordered a new one to test, should arrive tomorrow. Any ideas in case this isn't the problem? Could it be a motherboard issue? I'm new to building PCs so let's not rule out beginner mistakes.
 
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Solution
From what you've described, I'd lean to the PSU too The RMX is a great PSU, but like all manufacturers, you could just have a bad unit.
Wait for the new PSU, hopefully that sorts it.

Are you OC'ing anything? if so maybe run it without any OC's (CPU or GPU) and see if that makes a difference.
From what you've described, I'd lean to the PSU too The RMX is a great PSU, but like all manufacturers, you could just have a bad unit.
Wait for the new PSU, hopefully that sorts it.

Are you OC'ing anything? if so maybe run it without any OC's (CPU or GPU) and see if that makes a difference.
 
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Solution
May 16, 2019
6
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Hi!

Thanks for replying :)

I experimented with overclocking soon after first building the PC, but I reverted to default bios settings after noticing the random shutdowns.

Often what happens is that the computer will shut off and then enter this weird "pseudo off" state where the power button LED stays on (its an NZXT h200 case) and the ram sticks RGB stays enabled. When the computer is in this state, the fans stop spinning and the cooler master cpu cooler LEDs (and fan LEDs) are off, but the ethernet LED on the motherboard stays on and the cooler master controller (for the cpu cooler and fan RGB) LEDs are lit. Seems like the motherboard is still getting power, but maybe insufficient power for the computer to turn on? I suspected maybe that the CPU plug was badly inserted but that doesn't seem to be the problem.

Otherwise, it's a hard shut off where the ram sticks and case power button go dark, but even in this state, the motherboard ethernet light and the cooler master RGB controller stay on.

In either case, the case power button becomes unresponsive and the only way to turn the system back on is just to wait until it decides to power back on by itself... even toggling the PSU switch off and on doesn't seem to reenable the button to work. However, I've noticed that holding the power button down while the system is in the "pseudo off" state will cause it to enter the hard shut off state described above.

I thought that the case power button could be the issue, but it seems to work totally fine unless the PC decides to shut down by itself.

UPDATE: while in the "hard shut off" state, the PC just now attempted to reboot, but failed and entered the "soft shut off" state (or what I previously called the pseudo off state), where the RAM sticks and power button are now lit up. When it attempted to boot, the case fan LEDs lit up and started to spin momentarily before powering down completely.

UPDATE UPDATE: Soon after entering the soft off state, the computer managed to turn on, but went into the hard off state just before booting Windows... 1 second after the computer lit up again and managed to fully reboot into Windows... I'm expecting it to shut off again soon. Sorry, for the bombardment, but I'm trying to give you an idea of what is going on.
 
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rscheetah30

Dignified
Jun 8, 2018
292
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15,615
I recently went through a very similar issue, what solved it for me was rebuilding the Windows 10 boot record.

Take a look at this guide:


If this doesn't work for you(I didn't know this when I had the issue), do what I did, I booted through the Windows 7 dvd, then when prompted to pick a drive to install it on I deleted the OS drive completely and reinstalled Windows on it.

Simply deleting the malfunctioning Windows drive stopped the constant reboots/turn offs.

Good Luck and let us know what happened!
 
May 16, 2019
6
0
10
I recently went through a very similar issue, what solved it for me was rebuilding the Windows 10 boot record.

Take a look at this guide:


If this doesn't work for you(I didn't know this when I had the issue), do what I did, I booted through the Windows 7 dvd, then when prompted to pick a drive to install it on I deleted the OS drive completely and reinstalled Windows on it.

Simply deleting the malfunctioning Windows drive stopped the constant reboots/turn offs.

Good Luck and let us know what happened!
Thanks! Actually, I already have tried reinstalling Windows 10 and I’ve updated the Asus BIOS to the newest version. However, the shutdowns are persistant and seem to occur even in the BIOS when the system isn’t booted into Windows. Also, when these shutdowns happen, there is no blue screen or shut down prompt... it just turns off. I feel like this pretty much rules out Windows as a problem, no? Hopefully the new PSU fixes the problem and I’ll let you know what happens either way :)
 

rscheetah30

Dignified
Jun 8, 2018
292
7
15,615
Thanks! Actually, I already have tried reinstalling Windows 10 and I’ve updated the Asus BIOS to the newest version. However, the shutdowns are persistant and seem to occur even in the BIOS when the system isn’t booted into Windows. Also, when these shutdowns happen, there is no blue screen or shut down prompt... it just turns off. I feel like this pretty much rules out Windows as a problem, no? Hopefully the new PSU fixes the problem and I’ll let you know what happens either way :)

Actually when I had this same issue my pc would reboot even before reaching Windows or even its loading logo. It was so random sometimes it would reboot after 3 seconds on. What I did notice though was that the more I left it alone and turned off(I had to switch off the psu), the more time I had to tinker with it on afterwards. That's when I decided to delete the OS drive and voila, it solved the issue.
 
May 16, 2019
6
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10
Actually when I had this same issue my pc would reboot even before reaching Windows or even its loading logo. It was so random sometimes it would reboot after 3 seconds on. What I did notice though was that the more I left it alone and turned off(I had to switch off the psu), the more time I had to tinker with it on afterwards. That's when I decided to delete the OS drive and voila, it solved the issue.
Okay I’ll definitely try this out after I test the new PSU today. The problem is that my computer seems to be getting worse and I can hardly ever get it to POST anymore. The power button is unresponsive. If it’s not the PSU, I’ll try clearing the CMOS and breadboarding...
 
May 16, 2019
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So I have received my new PSU (Corsair RM750x) and have installed it. When I pressed the power button everything turned on and is now working as expected with no random shut downs! I only just installed it so I have to see if the system is fully stable but so far so good!