[SOLVED] Newly built PC turns on, then immediately restarts

[Cwena]

Around 5 months ago, I built a PC (parts are listed below). Since then, it has been working absolutely perfectly however I've recently encountered a really serious problem.

When I turn the PC on, the lights come on on the motherboard, fans start spinning, and it does start to post. However, usually after a few seconds, there's a noise (I think from the PSU) and the PC completely turns off before starting up again, with the process continuing indefinitely unless power is cut. I thought it was a temporary issue as yesterday it stayed on for around 20 minutes, allowing me to log into Windows. However, it then turned off again and the fault continued.

I have attempted to troubleshoot this however I am at a loss - my current theory is that there's some kind of issue with the PSU, however considering how new the build I have no idea why it has failed so quickly. Any insights or suggestions would be greatly appreciated.

Thank you all in advance!

PC Specs:
CPU: Intel i5-11400
Motherboard: MSI B560 Pro-VDH WiFi Micro ATX LGA1200
Memory: Team T-Force Dark z 16gb DDR4-3200 CL16
Storage: Kingston A2000 1TB M.2-2280
GPU: EVGA GeForce GTX 1050ti
Case: Cooler Master MasterBox NR400 MicroATX
PSU: Corsair CXM 550W 80+ Bronze Certified Semi-modular ATX Power Supply

 

[jay32267]

I realize the PSU is only two years old....but when I have had this happen....it has been the power supply quite a few times.
if you could find one just to swap in....that would be great from a troubleshooting standpoint.

 

[Cwena]

I realize the PSU is only two years old....but when I have had this happen....it has been the power supply quite a few times.
if you could find one just to swap in....that would be great from a troubleshooting standpoint.

Thanks so much for getting back to me!
I have done the paperclip test with the PSU and it runs absolutely fine, though I'm not sure if that necessarily rules it out as the problem component? Outside of it being the PSU I have absolutely no idea... it feels like something is shorting perhaps though I can't see anything that's obviously causing the issue

 

[jay32267]

You may be able to check the PSU voltages in the BIOS.....although not under load.
You can also check them with HWInfo if your motherboard reports them.
The three main voltages....12, 5 and 3.3 should remain within 5% of those values always.....or swap in another PSU.

 

[Cwena]

So I've noticed something: when the PC turns off there's a red light which flashes on the motherboard next to the CPU label. I'm assuming that means the problem is with the CPU in some way?

 

[jay32267]

That light can come on for other reasons besides a problem with the CPU.
I've seen it come on for a memory problem, a power supply problem or the wrong BIOS.
Most of the time I've seen it lit...it wasn't for the actual CPU itself.

 

[Cwena]

That light can come on for other reasons besides a problem with the CPU.
I've seen it come on for a memory problem, a power supply problem or the wrong BIOS.
Most of the time I've seen it lit...it wasn't for the actual CPU itself.

That makes sense, honestly thank you for all your help it's so appreciated. I did a few troubleshooting steps such as taking out RAM, checking fan connectors etc. and it still wasn't working. Then I tried turning it on again and it has been running now with no issue for at least 15 minutes. I am so beyond confused! 😂

 

[jay32267]

Faulty power supplies will do that.
Keep in mind I'm not 100% on the PSU....but it is what I would place my bet on.
I definitely don't think it's software related.
You could try and reset the CMOS.....but I don't think that's what it is....but it won't hurt.
I don't think it's the CPU because it rarely is.
You could try one stick of RAM in the appropriate slot....but it sounds like you may have already done that.
This is why I'm leaning on PSU.
It could also be the motherboard....but I would pick PSU over motherboard.