Odd power on issue with new build - help please

pahkle

pahkle

pahkle

Associate
Joined
12 Jul 2016
Posts
8
Dear OCers; please help.

I recently bought a new set of components and built a system.
It runs fine, except that sometimes it won't power on from the switch. Not a flicker of life, although the mobo power light is on. If I disconnect the power from mains, leave it for a 10 minutes, then it will work again. I've updated the BIOS to the latest version (1801), but the issue still persists.

Do you have any idea what might be going on?

Thanks for any help you can offer.

New Components:
XFX XTR Black Edition 1250W 80 Plus Gold Modular Power Supply
Asus Z170 Sabertooth Mark 1 USB 3.1 Intel Z170 (Socket 1151) DDR4 ATX Motherboard
Avexir Core Blue Series 32GB (4x8GB) DDR4 PC4-19200C16 2400MHz Quad Channel Kit
Kingston 480GB SSDNow UV400 Drive SATA 6Gb/s 2.5" (7mm height) Solid State Hard Drive
Intel Core i5-6600K 3.9GHz (Skylake) Socket LGA1151 Processor - Retail
Corsair Hydro H90 140mm High Performance Liquid CPU Cooler
Reused components:
Asus Nvidia 750Ti
 
Does the mobo light come on then turn off straight after?

Perhaps it could be a dodgy cable, try your monitor's cable in the PSU and see if that fixes the issue.
 
^I dont believe that to be the source of the problem at all.

Easy way to find the problem- Try turning the machine on and off several times, but turn it on by shorting the PWR button pins on the motherboard with a screwdriver (just touch screwdriver or your choice of metal object) to those and only those pins. If it works every time without a hitch, you know there is an issue with your case's power switch. If it doesn't work every time, there is an issue with the motherboard's connection to the PWR header pins.

If the second option turns out to be the case, I suggest an RMA of that board ASAP..:)

I did an apprenticeship as a computer technician at a shop so I know these things.
 
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Reset all power connectors
Pwrsw and pwreset
Can u turn it off on in an old case ?
Can u turn it off on without case?
RMA case.
Does the case get cold when turned off? I had an Asus mother board that would be a real pita from cold boot
 
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Thank you for your help. A little more info:

Shorting the power pins does not avoid the issue (thus button probably ok).

Also, restarting the PC does not cause a problem; however powering it off then turning on again does.

Once the PC is on it is fine, stays on, works normally. It just has this refractory period between powering off and switching on again.

Is it worth taking to a shop so they can swap out key components?
 
OP, it could be your PSU. I had a very similar issue with my Seasonic unit around 18 months ago. Once the PC was up it could run all week, but from cold it just would not start consistently. Something to do with the 5v running out of spec if memory serves correct. Got another unit you can test the board on?
 
Same issue with a Corsair AX650 which I had to RMA.

From cold sometimes you press power button and nothing, unplug PSU, wait several minutes and it would boot and run fine until I next shut it down.

And interestingly, my AX650 was a Seasonic unit, implosiveturnips PSU was a Seasonic unit and I believe this XFX PSU is a seasonic unit also.
 
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Thank you so much for your thoughs.
Some good news:
I found an old PSU - no problems with it installed.
I got hold of a friend's PC and put my XFX PSU in... it recreated the same problem!

The thing is, this is actually the second PSU I've had from OC. The previous one was a corsair 1200w, and it would cut out while under load.
It seems odd to have two dud PSUs in a row, especially when they are both higher end units.
Could it be that the motherboard is damaging them somehow?
 
psu paperclip test will confirm it (psu just connected to power)

To perform t he PSU Paper Clip test, we’ll need to e
xamine the power supply connectors
closely and find the one that has a lone green wire
. Ninety nine percent of the time, this green
wire is located on pin 14 on the bigger connector.
In addition to the green wire, locate the
other black wires that are present in the connector

connect green to black (remove pclip straightaway or it will switch off again)
 
I have this exact issue on my computer. It won't power on via case switch or the motherboard switch. Disconnect cables/usb device and it powers on fine and will remain on all day allmost like it can't handle the about of power need to post. Only happens when the computer is off over night.
My psu is a Corsair RM750.
 
Paperclip test: the PSU goes on and off fine (note this is now totally unplugged PSU with no load).

Digital heavens - that is odd indeed. presumably no evidence of other problems evolving over time?
 
FYI:
Have returned the PSU, which it seems is definitely faulty.
Even though the paperclip test worked whilst totally disconnected, it would not start when back in the system. The PSU did, however, emit a soft whine after pressing the ON button.

Thank you all for your help!
 
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