New Build PC suddenly won't POST

[Zoom7000]

So I just built a new system yesterday.

CPU: AMD Ryzen 7 5800X
Motherboard: MSI MAG X570 Tomahawk
RAM: Corsair Vengeance 32GB (2 x 16GB)
HDD: 1TB NVMe
Cooler: Corsair iCue H150i Elite Capellix
PSU: Corsair RM750
Case: Lian Li O11-Dynamic
GPU: Reused GTX 970

I put it altogether, POST was fine, installed Windows 10, installed updates, updated BIOS, used the PC for several hours, productivity, video calls, no problem. About 6 hours later, just whilst sat watching YouTube, Windows shut down but the PC was still powered and fans were running. I powered down the system and turned it on again and now the machine refuses to POST at all.

I reseated the RAM, GPU, checked all the cables, tried with 1 stick of RAM, reset the CMOS (by removing the battery) but no luck at all. I don't have any warning beeps or any warning lights on the onboard EZ Debug LED.

The PC was totally working fine and then after several hours, it just shut down and stopped. I was checking my temps as it was a brand new build and the CPU was stable at around 29 to 32 degrees.

Any ideas?

[zerocool1431]

See if it boots without any ram installed in the system.

Clear the CMOS.

[Zoom7000]

Tried without RAM. No luck.

 

I removed the battery for 30 seconds. Would that be sufficient, or would I have to short the jumper?

[seban]

11 minutes ago, Zoom7000 said:

So I just built a new system yesterday.

CPU: AMD Ryzen 7 5800X
Motherboard: MSI MAG X570 Tomahawk
RAM: Corsair Vengeance 32GB (2 x 16GB)
HDD: 1TB NVMe
Cooler: Corsair iCue H150i Elite Capellix
PSU: Corsair RM750
Case: Lian Li O11-Dynamic
GPU: Reused GTX 970

I put it altogether, POST was fine, installed Windows 10, installed updates, updated BIOS, used the PC for several hours, productivity, video calls, no problem. About 6 hours later, just whilst sat watching YouTube, Windows shut down but the PC was still powered and fans were running. I powered down the system and turned it on again and now the machine refuses to POST at all.

I reseated the RAM, GPU, checked all the cables, tried with 1 stick of RAM, reset the CMOS (by removing the battery) but no luck at all. I don't have any warning beeps or any warning lights on the onboard EZ Debug LED.

The PC was totally working fine and then after several hours, it just shut down and stopped. I was checking my temps as it was a brand new build and the CPU was stable at around 29 to 32 degrees.

Any ideas?

this could legit be anything, try a different PSU cable and we'll start from there.

[MorbidAngel]

Just now, Zoom7000 said:

Tried without RAM. No luck.

 

I removed the battery for 30 seconds. Would that be sufficient, or would I have to short the jumper?

Usually it's fine to just remove the battery, but if you can it wouldn't hurt to short it but I don't think it's necessary. Also have you tried the RAM sticks in different slots? Like one stick in slot #1, then #2 etc? That worked for me when my motherboard broke. It only worked in #1 with 1 stick of RAM.

[Zoom7000]

Just now, 1ppOverheat said:

this could legit be anything, try a different PSU cable and we'll start from there.

Which cable should I replace? 24 pin? 8 pin CPU? GPU cable?

[seban]

1 minute ago, Zoom7000 said:

Which cable should I replace? 24 pin? 8 pin CPU? GPU cable?

the PSU power cord i meant 

[Zoom7000]

Okay, well, I'll try another power lead. Although the system does power on. I just don't get a POST display.

[MorbidAngel]

2 minutes ago, Zoom7000 said:

Okay, well, I'll try another power lead. Although the system does power on. I just don't get a POST display.

Probably a long shot but have you made sure it's not just your HDMI or DP cable that is loose or something else monitor related? Do you have another monitor you can try?

[seban]

2 minutes ago, Zoom7000 said:

Okay, well, I'll try another power lead. Although the system does power on. I just don't get a POST display.

please do, and then reply to this.. the reason why i want you to do this is because sometimes the cable just goes bad and this happened to me actually and fixed my post problem..

[Zoom7000]

1 minute ago, MorbidAngel said:

Probably a long shot but have you made sure it's not just your HDMI or DP cable that is loose or something else monitor related? Do you have another monitor you can try?

I've got a dual monitor set up with 2 DisplayPort cables and also HDMI too. Can't get a display on either screen with either input.

 

Just now, 1ppOverheat said:

please do, and then reply to this.. the reason why i want you to do this is because sometimes the cable just goes bad and this happened to me actually and fixed my post problem..

It's a brand new cable, but, I'll give it a try as soon as I'm home and then update here.

[Vins69]

If you have it try with another power supply

[Vins69]

The more I read, the more it sounds to me like a power supply failure

[Zoom7000]

Just now, Vins69 said:

The more I read, the more it sounds to me like a power supply failure

Just out of interest, what makes you think that? I only ask because wouldn't a faulty PSU cause the system to not power on at all?

[Vins69]

I had a PC from a friend with similar synthoms and after digging it was the PSU which was able to start the led, the system and GPU fans but not the whole PC...

[seban]

6 minutes ago, Zoom7000 said:

Just out of interest, what makes you think that? I only ask because wouldn't a faulty PSU cause the system to not power on at all?

nope

[seban]

7 minutes ago, Zoom7000 said:

Just out of interest, what makes you think that? I only ask because wouldn't a faulty PSU cause the system to not power on at all?

PSU is almost always the first thing to consider checking out when random crashes (exactly like these) happen. So its just best to get that out of the way right away.

[boggy77]

33 minutes ago, Zoom7000 said:

I removed the battery for 30 seconds. Would that be sufficient, or would I have to short the jumper?

shorting the jumper is the correct/recommended way to clear cmos, not removing the battery.

[Useless Soveriegn]

Try reinstalling you bios version.

 

I had similar odd booting behavour when i installed my 5600x on x570, i tried various things to try and fix it but to no avail. I let my friend try fix it and after he update the bios its all worked fine even tho I'd already updated. Figured it was a botched install or something, haven't had issues since

[Zoom7000]

24 minutes ago, Useless Soveriegn said:

Try reinstalling you bios version.

 

I had similar odd booting behavour when i installed my 5600x on x570, i tried various things to try and fix it but to no avail. I let my friend try fix it and after he update the bios its all worked fine even tho I'd already updated. Figured it was a botched install or something, haven't had issues since

How would I reinstall the BIOS without getting a display? Is it something to do with the Flash CMOS button on the rear I/O shield?

[Useless Soveriegn]

Google search your own board for more spefic instruction im too lazy

[Zoom7000]

I did update the BIOS, but I'll give that a try. Thanks.

[Zoom7000]

So, I tested the following:

 

Tried another power cable (kettle lead)

Reset CMOS (both shorting and battery reseat, holding down the power for 20 seconds before powering back on)

Tried another working GPU (GTX 720)

Tried 2 working PSUs

Tried both sticks of RAM individually

Tried booting without the m.2 NVMe

Reseated the CPU

Flash BIOS via USB (latest version - v15)

Flash BIOS via USB (previous version - v14)

 

Still no luck. I'm totally stumped. I'm gonna try to get my hands on another CPU. Failing that, it could only be the motherboard, right?

[Vins69]

Yep, although a faulty motherboard completing the BIOS upgrade via usb seems a bit strange to me...

 

There are also some rumors about faulty Ryzen 5x00

https://hexus.net/tech/news/cpu/147438-no-evidence-high-ryzen-5000-cpu-failure-rates-seen-europe/

 

but let's see if you're able to try with another cpu, at this point you've already tried anything!

[Zoom7000]

So, managed to get my hands on a Ryzen 3 2200G, I just installed it. And... Now I get a CPU warning light!

But I don't get any warning light at all with the 5800X

 

What does that mean?!