SOLVED: Critical Failure, Need Help! PC turns on and immidiately off

Ok, first, let me thank you for clicking on my clickbait subject line lol…

PC started this randomly this morning… no power outages, etc… just one day she’s fine, next this.

Looks to me like short protection (hence, I removed as much as I could)… wondering if the internet has any ideas on the next diagnostic steps - how can I determine if this is the mobo, psu, cpu… I’m assuming we’re likely talking one of those three?

Talk to me people - what you think :slight_smile:


Can’t play that video…


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Linked Video

<<<Let’s try it this way?>>>


unhook the front panel reset and power switches, then jump the power switch with a appropriate sized screwdriver to turn on. you may have a bad power switch.
if that fails unhook the PSU and try a new one.
i think its the power switch because the mobo led’s stay on, leading me to believe its not a internal PSU shutdown due to a short (which would kill all power).
although it could be the psu has failed in a way that doesnt provide enough power to start the board.

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The mobo LEDs may be getting power from stand by mode of the PSU. So not an indicator that it’s 100% fine.

I’d diagnose the PSU first tho, do you have a spare one?

Added #helpdesk and edited the title a bit so people can see the post better.

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I can get a hold of a spare PSU - I’ll try the switch first when I get home from work, then if that doesn’t work I’ll go to the spare PSU idea…

The switch seems to work on the first try… then becomes unresponsive… like the mobo has a fault protecting that disables the switch?

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Video won’t play for me…

My advice is to always begin by removing everything that you don’t need to POST. Disconnect all periphials (usually SATA devices).
All you need ot POST is…
4-Power Supply (plugged into the Motherboard 24pin and CPU 4/8pin
5-Video card (only if your board does not support integrated graphics)
If your PC supports integrated graphics, plug your monitor into the motherboard HDMI or DP.

If you POST properly, you can troubleshoot by plugging in each peripheral from there. If you don’t POST, you know the issue is with one of those 4, and should start by swapping out the PSU.

I had this same problem with a friends PC. Turns out it was one of the SATA PSU cables. GL

this worked for me

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Only thing plugged in was the power cable… removed 3/4 ram, gpu, etc… but didn’t think about the SATA - that’s a good call.

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Yeah try to just boot to BIOS/UEFI. I one had Molex-to-SATA cable short out and kill my SSD. Maybe your PSU is fancier than my garbage and detects than.

Fingers crossed for SATA cable lol… that would be IDEAL (/sooo cheap)

That looks like a short circuit 12V to ground, the double click is the relay in the PSU opening.

System specs would be interesting too.

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Interesting - so would that mean that it’s the PSU shorting, or some other component shorting the PSU and it’s grounding out to save shit?

CASE: CaseLabs Bullet BH4
MOBO: Asus ROG Strix Z270I Gaming Mini ITX
CPU: i7-8700K
RAM: 16Gb GSkill Trident Z
GPU: EVGA 1080 Classified
PSU: Corsair SF600 SFX
CPU COOLER: Noctua NH-L9x65
STORAGE: 1tb sata SSD, 512Gb Nvme SSD
COOLING: 2xNoctua NF-F12 (main), 1xNoctua NF-A8 (lower)

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Not the PSU shorting out, just the overcurrent protection kicking in. Try unplugging all but the cables that are used on the PSU end.

Do you have any other PSU that can power the system on hand?

Also: Take a look under the motherboard, maybe there is a loose screw there.


Thanks guys - I’ll be heading home soon and will update you once I start trying some of this.


Good luck.

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Hey Everyone,

Thanks for your help… got me to stop thinking about faulty RAM, GPU, Mobo shorts and look at the basics… swapped in another PSU and she fired right up.

I didn’t really consider the PSU… it’s a Corsair SF600 (not sure who made it for them) and it’s only a couple of years old, always run in a dust free area of the case with good airflow (an 80mm fan just for the lower part of the case, only housed a SSD and the PSU).

Anyways, I’ll begin the RMA process with Corsair and hopefully they’ve (whoever built it) gotten better at their SFX designs.



Glad you figured it out. Good thing it’s not a mobo :+1:

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Or a CPU lol…

On the plus side, spring cleaning the case :joy:


OEM for the SF450 and SF600 is Great Wall.
I prefer Delta Electronics or SeaSonic PSUs.