Asus dark hero startup issue ?

[karlosfandango]

Hi all
I have a Asus Crosshair VIII DarkHhero ...with an AMD 5900X , 32gb of Gskils ram

Had a few times over last few months since recieving board where the system wont power on.
You press power switch on case and nothing .
You press power button on motherboard ...nothing ....and its lit up white ...all rgb is working ( on when powered off )
If i turn off PSU and back then power it back on ...system boots fine.
It can then be fine for say 4 weeks ...then happen out the blue again.
Was ok with old motherboard....so only things that have changed is MB and CPU.

Tried reflashing bios back to earlier version ...no different.
Had new graphics card since last time so rules that out.
Tried taking ram sticks out ...no difference.

Seems starnge how can run for weeks without issue ( but dont use it every day )

Im using an EVGA supernova 850W PSU.

Not major issue as all have to do is power off PSU and all good again ...but got to be something wrong.
Asus say sounds like something tripping PSU protection ...will have to try unpluging 24 pin and 8 pin cables next time , then plug back in to see if motherboard or psu .

Any help most appreciated.
Karl

[Doco]

When the motherboard doesn't turn on does any code show up on the leds on the top of the board that might help narrow down what the issue may be?

[RedSector73]

Turning off the PSU or needing to unplugging suggests you have a dead short problem, and it is clearly quite random. I would be looking for something like a power cord shorting in the system, doubt standoff screw.

You didn't meantion cooling solution for the CPU. I would have a look here as well.

Dodgy switch in case.
Dodgy USB connector.
Dodgy HDMI cable.
Check you have all power cables fully seated on the motherboard / clipped. Inclusive the two EATX above cpu, top left of motherboard.

Really hard to nail anything as random as 4 weeks ok then fault but the above is some of the areas I would start looking.

[karlosfandango]

Hi
There is no post codes coming up or lights underneath it ...just basically when press case switch or start button on motherboard ..it does nothing .
As for cooler ...im using a Asus Ryujin 360 AIO
Yes strange how its intermittent.
Once working have no issues what so ever...can turn off and on all night ..no issues .
I was going to try unplugging the extra 4 pin power connector at top of MB ...as heard its not really needed....worth a try as did not have that on my other board.
Ill will check all power connections over weekend ...and maybe try upluging some usb headers ...but most of them are needed for ICUE fans etc ...but they never had issues with old setup .
Only thing added on this board is a usb 3 header as case has usb 3 front ports ( lian li ) ...and old asus z170 deluxe MB didnt have that.
Might unplug that .

Many thanks
Karl

[RedSector73]

I was going to try unplugging the extra 4 pin power connector at top of MB ...as heard its not really needed....worth a try as did not have that on my other board.

Don't what you read isnt always true, it is needed. DOCP problems have been resolved directly by plugging both in and fair few other issues. BOTH is best and 100% certain this is not source issue for you.

Just does not start up... case switch could be sus, try onboard on/off and see if this works. However if you must turn off power supply this normally indicates a dead short condition or even over-voltage / something is tripping PSU protection mechanism.

[karlosfandango]

Hi
Power switch on MB has same issue

Karl

[karlosfandango]

so would it be worth turning off power to usb ports when pc is shut down via bios ? thats if possible.... to elliminate usb ports ?
Thanks
Karl

[karlosfandango]

ok ... so been thinking if had anything new after having new MB and CPU.
All i can think of is i had a new Corsair K100 keyboard with nexus addon screen and
new corsair wireless mouse about 3 weeks after getting MB up and running.
Could the usb keyboard cause this issue ? or anything connected via usb may cause this ?

Also if the PSU is in protection mode , would there be any power to MB ...as the RGB lights are still working ( have them set to on when MB is powered down )
and also start button is lit up.

I have been into bios and set usb power to off when in S5 state ...which guessing is powered down.

Many thanks for the help
Karl

[karlosfandango]

right ..another update.
So been trying pc and all seems fine ...so turned off pc and thought would power up straight away ....which it did ...but after 2 seconds i decided i wanted to power off again so held power button down ( pc hadnt even got to bios splash screen}
PC would not do anything again.

So tried disconning usb hub connectors , no change , tried 8 pin at top of board and red light came on next to it ...so plugged it back in ....tried 4 pin next to it ....still nothing when pressing power button on MB ( its lit up white and rgb logo still working )
Tried disconning HDMI cable , usb cables for keyboard etc ...nothing .
Tried removing power button from case to motherboard ...still nothing.
Removed usb 3 header ...nothing.

Only one forgot to try was usb 3.2 header ...think thats what it is.

In the end i removed the 24 pin cable and reconnected ...press star button and away it went.

Tried to replicate the issue by holding power button ...but wont happen now.

Can ram overclock cause this ? as now put back to standard ...or auto.

So basically i pulled the 24 pin to get working instead of turning psu off ....if psu protection ...would pulling 24 pin clear issue or would you still have to power psu off ??

many thanks
karl

[karlosfandango]

another update lol
managed to replicate issue ....seems if leave pc on for a bit i can get it to do it.
turn pc off ...started up then held power switch on case ..usually it will just restart pc ...but when happens pc will shut down and nothing will happen when you press button.
so tried usb 3.2 or whatever it is lol ...still noting .
so though , reset bios ....held in bios reset button for 10 seconds ...and guess what ...the sytem then powered up when pressed button.
So thought would try again ...straight way ...and got it to do it after 3 attemps ...pressed bios button reset and worked again .
Now ...as it had reset bios ...no overclocks were set ...so guessing second time after bios reset was noting to do with ram overclock.
Could it be ram issue ? worth taking out one stick ? running 2 16gb sticks of Gskill trident z

update again ...got it to do it again ..so took out 1 stick of ram ...though had cured it ..but no ..so took out both and kept starting and powering off straight away ...nothing ..no issue and tried it 20 times.
so put both sticks back in ..and nothing for another 20 times ..but does motherboard have to recognise ram ( needs more time than 3 secs ?
so wondering if does it again now ...could it be down to ram ?

saga continues lol ...just tried it again ...happened ...so took out all ram ...reset bios and it started again ..so tried few times holding power button ..and it happened again with no ram ...inserted ram and reset bios ..wouldnt happen again after 15 tries ...but guessing now pc has booted up properly ...the issue will continue .

Now is this still ram or something else ...as happened with no ram after bios reset...but pc hadnt got chance to recognise ram...dunno
would faulty psu cause any of this ? weird !!!

Karl