[SOLVED] PSU refuse to power the motherboard

[Saltcandy]

My apologies if I posted this in the wrong thread.
To be short, I have no idea why my motherboard does not boot. PSU worked in the paper clip test. But after connect the 24 pin and 8 pin power cable to the MOBO, the PSU refuse to power the MOBO when pressing the MOBO on board power button. Tried replacing and booting with only one stick of RAM, didn't work. Also tried reinstalling CPU, replacing cmos battery, resetting cmos.

I tried shorting the power switch pin with a screw driver and using the on board power switch to eliminate the possibility of a faulty PC case power button.
I successfully turned on the PSU by hot wiring PS_ON and Ground on the 24 pin connector. Tested the voltage of the 24 pin and 8 pin connector, all normal reading.

I made further measurements while the 24 pin and 8 pin connector is connected to the MOBO. When I press the on board Power button, the voltage of PS_ON dropped from 5.1V to 0.03V until i unplug the AC power of my PSU. Other pins had no power except the standby 5v power.

Specs:
(when performing the test, I removed them from the pc case and placed them on a insulating surface)
Asus strix x99
I7 6850k
Kingstone hyperx fury ddr4 8GBx3

Thank you very much for your help.

 

[richiestang_78]

What PSU is it?

 

[Saltcandy]

What PSU is it?

Hello
It's a cooler master V1000
Sorry I forgot to add PSU to the list.

Here is the full specs in case anyone is interested
Asus strix x99
I7 6850k
Bequiet dark rock pro 4
Kingstone hyperx fury 8GB x 3
ASUS gtx 1080a8g x2 (SLI)
Intel 600p 256GB m.2 ssd(my windows installed here)
Seagate iron wolf 6tb HDD
WD Blue 4tb HDD

 

[helpstar]

Is an ASUS Q-LED on?

only use one GPU in the upper PCIe slot

 

[Saltcandy]

Is an ASUS Q-LED on?

only use one GPU in the upper PCIe slot

Nope, nothing displayed on the Q-Led.
The motherboard is completely non responsive. CPU fans weren't running, I couldn't even hear the short beep you get when you boot a normal pc.

Thanks, I will try booting with one graphic card only.

 

[Saltcandy]

Nope, nothing displayed on the Q-Led.
The motherboard is completely non responsive. CPU fans weren't running, I couldn't even hear the short beep you get when you boot a normal pc.

Thanks, I will try booting with one graphic card only.

Sorry do you mean the Q-Led that displays numbers or the indicator LEDs?
For Q-Led, nothing was shown.
For indicator LEDs, yes but there were only two LEDs was lit. The PWR_LED and the RST_LED on the bottom of the MOBO. (The on board RGB lights was also working)

 

[Saltcandy]

Is an ASUS Q-LED on?

only use one GPU in the upper PCIe slot

Just tried booting with one graphic card.
Succeed on first try but after shutting down, the power button stopped working again and I can't boot the MOBO anymore. Probably because I disconnected the AC power for a while. Sometimes the MOBO will somehow boot on first try, but after that it will stop responding.

 

[helpstar]

Are all connectors tightly connected in the power supply as well?
Try different cables from your power supply

 

[Saltcandy]

Are all connectors tightly connected in the power supply as well?
Try different cables from your power supply

Yes they are firmly connected.
I just measured the 24 pin connector again and I found that the PWR_OK pin has 0v (should be 3-6v if PSU passed the selfcheck) even after PS_ON dropped from 5V to 0V(boot signal). Now I highly suspect I might have a faulty PSU. I will try replacing a new PSU.

 

[Saltcandy]

Is the corsair RM1000x good?

 

[jonnyguru]

Yes they are firmly connected.
I just measured the 24 pin connector again and I found that the PWR_OK pin has 0v (should be 3-6v if PSU passed the selfcheck) even after PS_ON dropped from 5V to 0V(boot signal). Now I highly suspect I might have a faulty PSU. I will try replacing a new PSU.

Your PSU is dead.

Is the corsair RM1000x good?

Sure. But so is the CM V1000 if you don't have a defective one.

 

[Saltcandy]

I just replaced the CM V1000 with a new corsair rm1000x and now my PC boots perfectly fine. I think it's safe to assume that i had a defective PSU.
Thank you everyone for your help, I really appreciate it.