At a loss.. PC shut down and won't (really) turn back on.

[CaptainSharkoon]

Yesterday it was during normal operation (just surfing on the Internet, CPU wasn’t noticeably hot, etc.) when my two months old PC suddenly switched off from one second to the other completely. Since then it can no longer be switched on or rather only seems to pull power for a very short time. The motherboard (the RGB LED) lights up normally when the power cable is connected and I just turn the switch at the back of the pc and lights up when I press the power button. The board also lights up very briefly (with two red LEDs on the CPU and DRAM) but only about half a second (and it sounds like a boot attempt, but it “hangs” somehow), however, it shuts down afterwards immediately. The GPU and case fans run during this half a second (when GPU connected, I disconnected it for now since its a very expensive one)

If I hold down the reset button on the case, the power seems to stay on at least for some more components as then also the CPU-cooler-screen (I have a water cooling system with LCD screen) comes on, but only as long as I press the RESET button down (together with the Power button). As soon as I release the button(s), everything immediately goes dark again.

My first thought was either a broken mainboard or possibly a broken PSU. But the fan of the PSU does turn as well. I also switched around the DRAM between the slots and different configs like 1 and 3 or 2 and 4 but no change. Same for just using a single RAM.

But I’m honestly at a loss especially because it was so completely without warning and before no problems occurred. Incidentally, there wasn’t a smell of burning or similar during or after the crash either. I also cannot find any obvious damage on the mainboard or any other component. Cables also seem to fit correctly as far as I can tell.

Could someone help with this? This build was super expensive and is only two months old. It houses a 4090 and a 7950x3d …..

I would have to send the whole thing into repair if this isnt fixable to the original online shop I got it from and that would include a rather lengthy transport. I would love to avoid it.

Many thanks already for advice.

Full specs are:

[ul]
[li]Corsair 5000D Airflow Case[/li][li]Be quiet! Straight Power 12 1000W 80Platinum BN338[/li][li]Asrock x670E Pro RS AM5[/li][li]Ryzen 7950x3d[/li][li]iCUE H150i Elite LCD XT[/li][li]DDR5 AM5 PC6000 G.skill 32 GB (2*16)[/li][li]Kingston M.2 Fury Renegade SSD 2 TB[/li][li]Inno3D RTX 4090[/li][li]Windows 11 Pro.[/li][/ul]

[xrobwx71]

Does it boot up with the GPU removed?

[CaptainSharkoon]

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Does it boot up with the GPU removed?

No, I posted a video on the discord for this forum as well. I disconnected the GPU for now.

[xrobwx71]

With these symptoms, the first thing I would suspect is the PSU. The fan running on the PSU does not indicate it’s delivering the power needed to boot your PC.

[CaptainSharkoon]

With these symptoms, the first thing I would suspect is the PSU. The fan running on the PSU does not indicate it’s delivering the power needed to boot your PC.

Mhh might be.. what about the Red light on the CPU? Could that also be the dead unit?

[phillpower2]

Before we suggest anything that requires opening up the case can you let us know if you are able to access the BIOS at all, if not sure how, restart and try continually tapping the Del key while the PC is powering up.

[CaptainSharkoon]

Before we suggest anything that requires opening up the case can you let us know if you are able to access the BIOS at all, if not sure how, restart and try continually tapping the Del key while the PC is powering up.

I cannot access anything as the pc powers off within half a second after pressing start button.

I cannot access the system at all. I tried resetting the cmos battery by removing it and inserting again after 5 minutes. Didn’t change anything.

[phillpower2]

A short circuit or overheating are two things that would cause such behaviour and another is a bad OC.

I tried resetting the cmos battery by removing it and inserting again after 5 minutes. Didn’t change anything.

Not a good sign but fwiw to do this effectively the power cord needs to be removed from the wall socket and the case power on button pressed and held in for twenty seconds both before and while the CMOS battery is removed, this gets rid of any residual charge in the BIOS chip and MB etc which in turn gets rid of any bad MB settings. such as OC profiles which as mentioned above could cause this type of behaviour, your RAM fits into this category, this explained below;

The RAM is not appropriate for your CPU, AMD state here up to 5200MHz and if you have XMP/EXPO enabled the RAM will get auto OCd past what the CPU can handle and the PC will become unstable.

Did you put this build together yourself or if not are you ok with working inside a computer.

[CaptainSharkoon]

A short circuit or overheating are two things that would cause such behaviour and another is a bad OC.

Not a good sign but fwiw to do this effectively the power cord needs to be removed from the wall socket and the case power on button pressed and held in for twenty seconds both before and while the CMOS battery is removed, this gets rid of any residual charge in the BIOS chip and MB etc which in turn gets rid of any bad MB settings. such as OC profiles which as mentioned above could cause this type of behaviour, your RAM fits into this category, this explained below;

The RAM is not appropriate for your CPU, AMD state here up to 5200MHz and if you have XMP/EXPO enabled the RAM will get auto OCd past what the CPU can handle and the PC will become unstable.

Did you put this build together yourself or if not are you ok with working inside a computer.

Well I did the things you mentioned when trying CMOs reset, but thanks for the hints.

The OC profiles might be a reason but the ram sticks say explicitly and expo compatible or something to that effect. So unsure if that could be it. I got the system via online shop and configured it myself from certain available components.

But maybe the RAM got fried anyway and both sticks are dead. I have no good way to test that though since I don’t have a replacement lying around. What I did test is trying both sticks individually in each slot and both in slots 1/3 and 2/4 (original configuration). Didn’t change anything.

[CaptainSharkoon]

A short circuit or overheating are two things that would cause such behaviour and another is a bad OC.

Not a good sign but fwiw to do this effectively the power cord needs to be removed from the wall socket and the case power on button pressed and held in for twenty seconds both before and while the CMOS battery is removed, this gets rid of any residual charge in the BIOS chip and MB etc which in turn gets rid of any bad MB settings. such as OC profiles which as mentioned above could cause this type of behaviour, your RAM fits into this category, this explained below;

The RAM is not appropriate for your CPU, AMD state here up to 5200MHz and if you have XMP/EXPO enabled the RAM will get auto OCd past what the CPU can handle and the PC will become unstable.

Did you put this build together yourself or if not are you ok with working inside a computer.

Concerning working in a computer, to a degree yes, but I certainly have no experience and not a good feeling for most stuff in there. Especially the many cables leading to the PSU and the mobo.[ATTACH type=“full”]12995[/ATTACH][ATTACH type=“full”]12996[/ATTACH]

[phillpower2]

I don’t like the look of that Corsair component hanging there :cautious:

The GPU and case fans run during this half a second (when GPU connected, I disconnected it for now since its a very expensive one)

The GPU must be completely removed from the PCI-E slot on the MB for the onboard video to work.

Have you physically removed the add on video card from the PCI-E slot on the MB and then stored the card in a safe place.

What are you using for a screen.

If you are not comfortable it would be best to seek the assistance of someone that is, as you say there is a lot of cash tied up in this rig.

I did the things you mentioned when trying CMOs reset,

Do this again but this time leave it overnight, leave the power cord disconnected, the CMOS battery out and the RAM out, power button pressed in for twenty seconds, leave like this overnight.

Next day, put just the one stick of RAM in slot B2 which is the fourth slot from the CPU.

Put the CMOS battery back in.

Connect the screen to the appropriate video port on the MB, connect the keyboard and the power cord, power up with your fingers crossed.

Something to keep in mind for the future, a CPU must be compatible with a MB whereas the RAM has to be compatible with both the CPU and the MB, this because a MB can be compatible with faster CPUs than the one in your list of parts and MB manufacturers often state RAM speeds that far exceed that which any compatible CPU in the board can handle.

Can I ask that you do not quote every reply as we have to read the full post to make sure nothing gets missed, thanks.

[CaptainSharkoon]

The component hangs there because the glue or whatever they used to pin it there has dried up I guess.

The GPU is in its box in an antistatic bag. The slot is empty.

I use a Dell S2721D screen (1440p).

I guess I could try the CMOS thing again overnight. But shouldn’t I keep the screen disconnected first? Just in case its some form of power problem that could fry other components. I am kinda paranoid right now that the more I try, the more might break (if its some power thing).

Concerning the 7950x3d being incompatible with 6000Mhz RAM..I didnt know that, I assumed the RAM being available for purchase in the online shop configurator would be RAM that works no problem with the CPU and Mobo. I mean it worked for 2 months I guess.

[phillpower2]

That is poor quality workmanship.

Please do as you see fit but you are at last chance saloon before having to return the PC.

Disconnecting the screen will do no harm if it puts your mind at ease.

The reason why I asked what you were using for a screen, many people use large screen TVs and with them you have to select the source of the signal that you want the TV to use, VGA port or HDMI for example, if you don`t select the correct source you get a No Signal message on the screen, not an issue here as you are using a dedicated PC screen and was just wanting to make sure that we covered all possibilities.

From my reply #8

[COLOR=rgb(184, 49, 47)]The RAM is not appropriate for your CPU, AMD state here up to 5200MHz and if you have XMP/EXPO enabled the RAM will get auto OCd past what the CPU can handle and the PC will become unstable.
[/COLOR]

[COLOR=rgb(184, 49, 47)]
You will note that I say that the RAM is not appropriate for your CPU, the words are carefully chosen because the RAM will work when EXPO is not enabled and the problem only arises when a user tries to enable EXPO.

Short version, you should only purchase RAM that is not above what the CPU can handle, if you do, you cannot enable EXPO thus making it redundant and atop of that you have spent cash on faster RAM that you cannot use with EXPO.[/color]

[CaptainSharkoon]

I thought so too after discovering that. Not sure how to repin it there though.

I now removed the CMOS battery again and it lies here before me now. I pressed the power button 30s while it was still in and after it was out again. Also I removed both RAM sticks. I will try latest tomorrow or maybe in like 5 hours, that should be certainly enough time.

Woould you think a BIOS flashback could help? Like doing a USB update without the PC needing to power up? (I think thats possible right? It has that button for it at the back of the MOBO)

[phillpower2]

Entirely up to yourself. we advise but it is your PC.

100% leave the BIOS alone, as long as you leave that alone you cannot be accused of bricking the MB with a bad BIOS flash, there is also the matter that there will be no BIOS to revert back to unless you have updated the BIOS since you got the PC.