Question PC won't turn on sometimes after shutdown or sleep (New Build)

[Ken6d0]

Hi, I just made a new build about a month ago but there's an issue that seems to be getting more apparent. Whenever I put the PC into sleep or shut it down, pressing the power button from the case or the 'start' button on the motherboard does not turn the pc back on. The RGB standby lights from the motherboard are still on. This issue does not happen every time its more of a 50/50 chance of it happening after a shutdown/sleep. The only way to fix it would be to flip the PSU switch on the back of the case to OFF until the motherboard lights turn off and then switch it back to ON which then allows the PC to boot without issues.

Seems like a possible PSU issue but was wondering if there's anything else I can try before looking at an RMA.
Thank you in advance.

System Specs:

Picture of system: prnt.sc/1vv5iw0

CPU: R9 5950x
GPU: RTX 3080 ti HOF
MB: Asus Crosshair Dark Hero III
RAM: Gskill 3600mhz Trident Z CL16 64GB
PSU: Corsair RM1000x

2TB 980 pro SSD + 4TB Iron wolf HDD

 

[Ken6d0]

It seems to be the motherboard that is the culprit. On the ROG forums there's a long thread with a bunch of people who own Dark Hero's who have the exact same issue, regardless of other components.

https://rog.asus.com/forum/showthread.php?125064-Asus-dark-hero-startup-issue/page4

 

[COLGeek]

Is your motherboard BIOS the most recent version available for it?

 

[Ken6d0]

Updated it to the latest one, still no luck

 

[COLGeek]

Did you install the latest AMD chipset drivers as well?

 

[Ken6d0]

Yeah they're up to date.

 

[COLGeek]

Anything overclocked (CPU, GPU, memory)?

 

[Ken6d0]

Anything overclocked (CPU, GPU, memory)?

GPU and CPU were but I reset the CMOS and BIOS. I've been running both of them on factory defaults with only DOCP since earlier today. Had same issue after putting PC to sleep for only 5 mins. Used old ram 16gb kit, still same issue.

If I remove the 24pin and plug it back in whilst the PSU is switched on it works when I press the power button. Maybe some static somewhere is being left in the motherboard on some shutdowns. Other board owners seem to have the same issue but I haven't yet discovered a fix.

 

[lambchickenmix]

Hey mate, what a coincidence that you posted this as I posted the same thing a few days priot. I am having the same issue, like literally the exact issue. I also thought it was my motherboard so I replaced the MSI MAG Z490 Tomahawk with the Aorus Ultra Z590 and the isssue came back within a day. I know every other part works so the only remaining one is the PSU. I've just bought a replacement unit and will replace it today, hopefully fixing it. I suspect that also might be your issue.

I've tested the PSU with a bridge and a tester which by all indications it passes as it turns on instantly. I have a feeling that the issue is when there is a load or it needs output power (i.e power button press), it doesn't work - which leads me to believe it has to be the PSU.