Well the excitement over my new build was short lived.  I got everything assembled after far too many hours, and when I went for my first boot up to my surprise the computer turned on as soon as i flicked the power switch on the back, without me using the power button up front.  Then it turned off a few seconds later, then on, then off etc.  There was a click each time it turned on and off.  The only way to get it to stay off was to kill the power with the rear button.

Any ideas?  A google search netted me mainly topics where it wouldn’t boot or it booted then shutdown, but I couldn’t find much about continuous power cycling or the computer turning on without pressing the power button.

What I did find was suggestions that the ram, cpu, motherboard or psu could be the culprit.  I tried reseating the ram and confirmed all power connections are snug.  No dice.  My issue is if it’s one of the motherboard, psu or cpu, i have no real way to figure out what is the culprit (combined with having zero interest in spending hours pulling everything apart again).  My only other psu is 650w and is not powerful enough for my new system.  I don’t have another cpu that will work in this motherboard and vice versa.  

I’m feeling stuck here, frustrated and not sure what to do next.

Thanks for any suggestions.

Edit:  I realized the one thing I could swap over from my old system to test was my ram, and it had no effect so I think a ram issue can be ruled out.

Edited July 24, 20205 yr by regis9

I am no expert, but maybe a faulty power switch button on the front of the computer case? Maybe the power switch wire connected to the motherboard is not connected correctly or "stuck" in some way?

Or maybe a missing stand off screw behind the motherboard is causing a short?

 

Did you check to make sure all the Front Panel Connectors are plugged correctly into the Connector block of the motherboard?

Greg

Unplug your front power button, then check the MB should have a boot button on the MB, turn the main power on and boot from that to test if ok.

Thanks for the replies everyone.  I’ve posted a video to better show what is going on.  There an initial slightly longer cycle, then it moves into repeating a much shorter power cycle on and off.  I still can’t understand why it turns on without me ever pressing the main power button up front.  As soon as power is delivered through the psu, it turns on.
 

Today I tried Removing my PSU and using the testing tool that came with it (if the fans run, it is working) and it worked.  Not sure how conclusive an included testing Tool is but if so, that would seem to rule out the PSU.  I reseated the GPU and reconnected the main motherboard power connector.  I also unplugged the power switch, reset switch and power leds from the motherboard.  I disconnected all hard drives other than the system drive.  None of this made a difference.  I’ve since reconnected the power and reset switch and no difference.

I’m running out of ideas, I may try to reseat the cpu and/or remove my 2080ti and put my old 1070 back in the reduce power consumption and then try using my old 650w power supply.  In the end though I feel like these are barking up the wrong tree and wonder if something is wrong with the case itself or how else the computer could be starting without me ever hitting the power switch?

12 hours ago, SlowFlyer said:

Or maybe a missing stand off screw behind the motherboard is causing a short?

My case has built in stand offs.

9 hours ago, G-RFRY said:

Unplug your front power button, then check the MB should have a boot button on the MB, turn the main power on and boot from that to test if ok.

Thanks, I do have a power button on the MB but the issue is that the computer  turns on as soon as the power switch on the psu is moved to the on position, pressing that button has no effect once the computer is on.

There should be a led read out that will give code see what the code is and look it up.

That mite help

Thanks, just had a look and there are no number lit up

1 hour ago, regis9 said:

Thanks, I do have a power button on the MB but the issue is that the computer  turns on as soon as the power switch on the psu is moved to the on position, pressing that button has no effect once the computer is on.

If I had already disconnected all cables from the front panel and checked PSU and other components.
I would check if the BIOS reset/cleanup pin is connected to the correct pins, also check other pins, my MB has a memory trainer pin also. (Don't know Your MB brand/model)
Also note that sometimes power buttons in the front panel might be stuck, even without You noticing.

If all fails, then I would take the long road:
Remove everything from the case.
Place the MB on a static free surface. Check the CPU is sitting properly, (Use the default CPU fan)
Add 1 or 2 mem sticks, check for proper sitting. (If possible 1 only)
Add the old video card (You can later try the new one)
Attach the PSU connectors.

Turn on the PSU switch and see if it boots properly to the BIOS when You press the Power Button or if it boots by itself.
- If it boots by itself You might have a broken MB.
- If that works as expected, then You had a "short circuit" somewhere in Your case that was causing the power up.
 

Thanks Ramon, I forgot to mention that I have tried both the bios flash and cmos clear buttons without any positive result.  They are integrated Into the rear panel of my motherboard (gigabyte z490 Aorus master).

just to confirm, are you suggesting adding everything back to the motherboard outside of the case to test or taking everything out and gradually reassembling it in the case?

Thanks again

I would test everything out of the box. Then if that works, add the essentials to the box and test again. Lastly connect all else.

Good luck

Edited July 24, 20205 yr by RamonB

This may or may not be anything, but I just tried again and after I turned the rear power switch off , everything shut down, but then the power/flashed back on for a split second before shutting down?

I can’t help but think there is power going places at times that it shouldn’t be.

Thanks, how do you test for functionality if it’s outside the case without the psu attached?

My cpu (i9 10900k) doesn’t Include a cooler So I’m Into my AIO cooler right away.

I realized I never actually posted my full build specs, here they are:

RTX2080ti (reused from my old build)

CPU: i9 10900k

Mobo: GIGABYTE Z490 AORUS Master

RAM: G.SKILL Ripjaws V Series 32GB (2 x 16GB) DDR4 3600 (CAS 16)

PSU: Seasonic FOCUS GX-850, 850W 80+ Gold

Cooler: EVGA CLC 280mm All-in-One RGB LED CPU Liquid Cooler

Case: Corsair Icue 465X RGB Mid-Tower ATX Smart Case, Black - CC-9011188-WW

Edited July 24, 20205 yr by regis9

Just now, regis9 said:

Thanks, how do you test for functionality if it’s outside the case without the psu attached?

 

For testing, I would also remove the PSU from the case, and attach the cooler outside.
If not possible then check all screws (PSU, MB, etc.)
 

 

Ok thanks, so basically building the pc outside of the case to eliminate any Interference from the case? 

11 minutes ago, regis9 said:

Ok thanks, so basically building the pc outside of the case to eliminate any Interference from the case? 

Correct. Unfortunately, we sometimes have to do that to eliminate components one by one.

One last thing: Check that both the PUMP and the FANS are working in the Cooler.
(Some years ago  I had an Intel Water Cooler and even though the pump made noise and the fans were functional it was the culprit for my PC shutting down just after booting it. Swapped to Corsair coolers ever since)

Edited July 24, 20205 yr by RamonB