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, replaced the CMOS battery, checked all the cables, but no luck at all. I don't have any warning beeps or any warning lights on the onboard EZ Debug LED. So, any idea what could be causing this?

 

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?

[3s-gtech]

Can you test the board on a bench, outside of the case? It’s most likely to be a motherboard issue (or PSU but that seems less likely here) as you’d tend to get beeps if it was CPU or RAM.

[Zoom7000]

Can you test the board on a bench, outside of the case? It’s most likely to be a motherboard issue (or PSU but that seems less likely here) as you’d tend to get beeps if it was CPU or RAM.

 

Gonna have to give it a try. No idea what else to do! I've tried with a single stick of RAM too. Still no luck. It's just annoying that I'll have to take the whole thing apart! 🤦♂️

[bald_pig]

I've seen similar behaviour from a faulty NVME before. When you say you powered down the PC, was it just from the front power button, or have you switched off/unplugged the PSU? Edited February 22, 2021 by Zoom7000

[Zoom7000]

I've seen similar behaviour from a faulty NVME before. When you say you powered down the PC, was it just from the front power button, or have you switched off/unplugged the PSU?

 

Initially I powered it down from the front power button. But during the diagnostics, I used the power button on the PSU, ensuring I discharged the power, as much as possible.

 

I tried powering on the system without the NVMe and it still wouldn't POST.

[Jawloms]

I had exactly this with an MSI motherboard and it was because I installed the RST driver but wasn't using RAID. Cleared the CMOS using the jumper and it all came back to life.

[Zoom7000]

I had exactly this with an MSI motherboard and it was because I installed the RST driver but wasn't using RAID. Cleared the CMOS using the jumper and it all came back to life.

 

I removed the battery for 30 seconds. Would this not be enough?

[Jawloms]

Possibly not, was it plugged in at the time?

 

I'd clear it with the jumper anyway just to check. Failing that, I found MSI support very helpful.

[Zoom7000]

How exactly do you clear with a jumper, without the actual jumper? Is it just a case of touching the 2 pins together with a screw driver?

[r0cketbev]

On the back of the board there is a flash bios button. That should clear any bios setting you have set up.

[Jawloms]

How exactly do you clear with a jumper, without the actual jumper? Is it just a case of touching the 2 pins together with a screw driver?

 

That should do it, but I just borrowed a jumper from another board I had lying about.

[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 bothsticks 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?

[Jawloms]

My MSI motherboard has LEDs on it showing how far through the POST it's getting. Does yours?

[chazzy2501]

if you were able to flash the bios (even using flashback) then the CPU, RAM and GFX are all good. Dumb stuff now like removing the board from the case to ensure there isn't something shorted, also disconnect the front panel connections and fans in case they're grounded or shorted.

 

I've seen an issue where a case had slightly different standoff mounts for the mobo which twisted the board enough to kill it. I've seen the wrong way round CPU bracket (underside) short stuff around the CPU. oh and standoffs installed where they shouldn't and touch the mobo.

 

in short (boom boom) it's worth taking the mobo out of the case.

[Dos_Box]

As a quick thought, have you updated the cooler firmware yet? Could be the BIOS update has fallen out with the cooler if that is all you had updated. It may be worth a shot.

*Yes, you can update the firmware on this cooler - https://help.corsair.com/hc/en-us/articles/360052794891-What-to-do-when-you-cannot-update-iCUE-Elite-Capellix-liquid-CPU-cooler-firmware

[Zoom7000]

As a quick thought, have you updated the cooler firmware yet? Could be the BIOS update has fallen out with the cooler if that is all you had updated. It may be worth a shot.

*Yes, you can update the firmware on this cooler - https://help.corsair.com/hc/en-us/articles/360052794891-What-to-do-when-you-cannot-update-iCUE-Elite-Capellix-liquid-CPU-cooler-firmware

 

Doesn't look like I'll be able to do that, because I can't get into Windows

[Zoom7000]

if you were able to flash the bios (even using flashback) then the CPU, RAM and GFX are all good. Dumb stuff now like removing the board from the case to ensure there isn't something shorted, also disconnect the front panel connections and fans in case they're grounded or shorted.

 

I've seen an issue where a case had slightly different standoff mounts for the mobo which twisted the board enough to kill it. I've seen the wrong way round CPU bracket (underside) short stuff around the CPU. oh and standoffs installed where they shouldn't and touch the mobo.

 

in short (boom boom) it's worth taking the mobo out of the case.

 

Just RMA'd the motherboard. After all the testing and process of ellmination, that's the only thing I can think of!

[Dos_Box]

Just RMA'd the motherboard. After all the testing and process of ellmination, that's the only thing I can think of!

 

Fingers crossed it's just that

[Zoom7000]

Fingers crossed it's just that

 

Indeed! I definitely hope so!

[Zoom7000]

Never really worked out whether it was the CPU or Motherboard that was faulty. CCL Online told me that they tested the board and it POSTed fine, even though I tested with 2 different CPUs and couldn't get it to. But, they agreed to refund me anyway... And I got a refund for the open box CPU from eBay.

 

I'm guessing the CPU was probably the obvious issue, but who knows. Either way, I bought another 5800X from Amazon and also went for a slightly better board, the MSI Meg X570 Unify and now have a decent working system!

 

EDIT: Signature updated! 🥳

Edited March 8, 2021 by Zoom7000