RM750 PSU shuts down on its own 30 seconds after jumping my motherboard

[rara4]

Hello everyone

I bought a corsair RM750 PSU, but it has a silent mode so the fans don't spin unless it's under high load.
When jumping my motherboard with a screwdriver, the PSU fan doesn't spin but it stops providing power to my motherboard 30-40 seconds after being on. It consistently shuts down after 40 seconds.
Is that a normal behavior ?

Thanks

[--SID--]

Or does the motherboard shut down the PSU?

 

Please list full system specs.

 

What was your previous PSU?

[rara4]

9 minutes ago, --SID-- said:

Or does the motherboard shut down the PSU?

 

Please list full system specs.

 

What was your previous PSU?

It's my first time building a pc, everything is brand new. ps: GPU fans don't spin either, and it doesn't POST (I tried both HDMI and DP)
I have a B550-F motherboard, ryzen 7 5800x cpu, zotac 3070 gpu, crucial 2x16GB ram, a samsung SSD and arctic freezer II aio (but I didn't plug it in yet, I wanted to see if everything else would work before).
In hindsight I thought everything was shutting down because the CPU had no cooler on it, maybe it overheats? That's what I was going to try today.
Yesterday I tried flashing the BIOS and clearing CMOS, neither worked. I think everything is wired properly to my PSU.

[--SID--]

1 minute ago, rara4 said:

In hindsight I thought everything would shut down because the CPU had no cooler on it, maybe it overheats?

You fired it up without a cooler? Why do people such stupid things!

[rara4]

13 minutes ago, --SID-- said:

You fired it up without a cooler? Why do people such stupid things!

Oh shit ok that was dumb I guess. I thought I would keep it simple and only plug CPU/GPU/PSU/RAM.
But my GPU fans don't rotate anyway. 
PS: My motherboard LEDS display VGA (white) & BOOT (green) at the same time. I will try plugging my GPU on the other PCIE slot too. Sorry about that

[Spotty]

If you're running the CPU without a cooler that would explain why the system is shutting down after about 30 seconds. It will overheat pretty quickly without a cooler and shutting down is the PCs way of protecting itself.

Finish assembling the PC and then update us if you still have issues.

[Somerandomtechyboi]

41 minutes ago, rara4 said:

the CPU had no cooler on it

Well no sht it shut down xD

 

This isnt a freaking pentium with low heat output, i can boot my e5000 pentiums without a cpu cooler just fine cause they are pentiums and they have low enough heat output, even managed to run one with just a fan and no cooler just because i can but at a pitifull 1.9ghz 0.82v, on prime95 smallest ffts temps are mid 70s which is pretty good for something without a freaking cpu cooler xD

 

 

This is a bloody ryzen and i dont think an 8 core would run very cool would it? Touch the ihs and youll burn your hand, heck when i run my pentiums without a fan at all even the substrate gets near burning hot, i can afford to abuse my poor cpus cause cheap (they go for less than 1$) but you have a new 8 core that costs 350$ or whatever its price is now, wouldnt you be concerned if the bloody cpu cooked itself to death? Well better hope the damn thing didnt exceed 120c cause above 120c then its pretty likely that thing is toast

[rara4]

6 hours ago, Spotty said:

If you're running the CPU without a cooler that would explain why the system is shutting down after about 30 seconds. It will overheat pretty quickly without a cooler and shutting down is the PCs way of protecting itself.

Finish assembling the PC and then update us if you still have issues.

Thank you so much, it seems to work literally after installing my AIO. You cannot realise how grateful I am for your help. Literally all my problems solved (Motherboard LED + GPU fans + POST + 30s PSU failure).
I will update here if anything occurs, in the meantime I want to say: thank you

[Mattias Edeslatt]

My guess is it could be that you didn't have a fan installed so the motherboard shut down as it got a no fan signal for the CPU. That feature is on by default, by this very reason...

 

But regardless if it auto-shutdown for CPU overheating protection or no fan signal, you should never ever start a PC without the cooler installed.

 

But you are correct that it is a good idea to test the setup with the RAM, CPU (+ cooler) and GPU before you install everything in the case, to eliminate troubleshooting if the machine doesn't boot after everything is installed. Then you know that it was all OK or if something is dead on arrival (DOA).

 

And there is also the golden rule to never install everything and close up the case, then it is almost guaranteed that it won't start or that you have installed the cables for the front IO the wrong way and so on.... besides it is always to get a visual confirmation that everything in OK, no leaks, all fans spins up and so on. And if you let the magic smoke out ^TM you definitely want to see where it comes out from, much easier diagnosing that way.