PC powers off for 1 second immediately (right when I turn it on), then turns on and stays on.

[Stefan_77]

Hello.
I've just assembled these:

Gigabyte H370M D3H
i3 8100
Patriot Viper Elite 2x4GB Kit (*)
ADATA SU800 128GB
Corsair CX450

(*) It says 2400Mhz on the package, but it showed up as 2133 in bios, turned on XMP and it then displayed as 2400

No graphics card. Not needed.
There was no internal speaker included with the mobo, nor the case.

When I turned it on for the first time (no monitor attached) it worked for a few seconds, then it powered off by itself for about 2 seconds (CPU fan, case molex connected fans stopped), turned back on, then back off / on / off...

... did that about 4 times, or 5 times in the first 30 seconds after I powered it on. Then it didn't happen again.

The next day the monitor arrived. I turned the PC on, after 2 seconds it turned off again for 1 second, then back on. And it stayed on. This time it did that only once. And it keeps doing the same. It keeps turning off for a second right after I turn it on.

Nothing strange happening besides that.

What could cause that behaviour, though? Is it something I should be worried about?

 

[electro_neanderthal]

It sounds like your motherboard is running some checks on the hardware... which is normal after the board is completely drained of power, like after a power outage or flipping the PSU switch off; but I'm not sure how normal it is to constantly do that. Does the motherboard manual say anything about that? You could try re-seating the RAM and power connections to see if it's just a loose or ill-fitted connection.

 

[Stefan_77]

It sounds like your motherboard is running some checks on the hardware... which is normal after the board is completely drained of power, like after a power outage or flipping the PSU switch off; but I'm not sure how normal it is to constantly do that. Does the motherboard manual say anything about that? You could try re-seating the RAM and power connections to see if it's just a loose or ill-fitted connection.

That must've been it.

I first powered it on with no monitor (it wasn't yet delivered to me) and obviously no OS installed. Powered it off, unplugged it... When the monitor arrived I've tested it again just to look around in the bios... So, the described problem showed up in these situations, and even after installing Windows 10 but without installing the motherboard (since it came with a CD, and I don't have an optical drive).

But now that Windows is installed and mobo as well, and I don't unplug it anymore either, it works just fine. I've also bought a speaker, there's just the one beep at power on, so everything looks right hardware wise.

On the performance part, though... it's a disaster. I've barely managed to install Windows using an USB (had to change something in the bios, forgot what), and installing the mobo from an USB was even worse. I kept getting a lot of errors, the E drive (the USB) kept disappearing, had to keep changing the USB port, I got a lot of "Not Responding" menu windows...

It's a new computer, first install... and it behaves like an old one, as if it's full of malware. The integrated graphics are kinda bad (didn't have this issue with integrated graphics in Haswell), playing an YouTube video is awful, the video looks blurry (most details are hardly detectable) and it's lagging, it skips certain portions to catch up, it looks as if it's some 20 frames / sec...

... all that while my 2007 laptop has no such issues whatsoever. I'm tired of forever having to find solutions to issues that shouldn't exist. What a waste of time!, for me, and others that are willing to help.

There's nearly nothing installed on this computer, and the single installed app sometimes won't open (no, it's not the app's fault, it works just fine on a lot of other W10 / 8 / 7 computers, including my W7 laptop).

And the 2nd monitor (HDMI connected) has no sound, and it keeps going black / "no signal" from time to time. Awful... I'm so disappointed.

 

[rune2h]

You should not be having such issues with the specs that you have listed. It could be a software/drivers issue. Are you certain you installed all of the proper drivers correctly (looks like you had some trouble via USB)?

 

[electro_neanderthal]

Ouch, that's not good. Assuming the Windows install was created using the official Windows Media Creation Tool, you shouldn't be having those issues; sounds like it can't keep up to light workloads. I'm pretty sure one of the parts is faulty - though I'm not sure if that's because the CPU is struggling or the motherboard is choking the system; and if any of that wasn't caused by the PSU.

I'd start by checking the PSU, since a faulty unit can damage other components. Then, and I think this is the issue, it could be the motherboard: not all handle power the same, and the several restarts in a row, if it was faulty, could have damaged the chipset. I would also check the CPU, to see if that's the cause (or become a victim). Whatever is wrong seems to be under warranty, and might even be RMA-able, so hopefully you can get this resolved.