Question Motherboard wont POST, screen stays black ?

Jul 7, 2021
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Hey everyone, this is my first question on here, first of all sorry for my bad english, not a native speaker here.

So recently i decided to build a mini-itx pc with parts i had laying around.

PC-Parts:
  • Asus MAXIMUS-VIII-IMPACT
  • 2x 8 Gb 3200Mhz Corsair vengeance ram
  • Intel i5 6600K
  • Msi gtx 1050 Ti (will get replaced)
  • Bequiet system Power 9 500W (I bought this one new)
  • Arctic Liquid Freezer II cpu cooler
  • case: Fractal core 500
  • Sandisk 2Tb SSD
Everything booted up just fine the first time, i could enter Bios and mobo would POST just fine.

Then i shut the system down and plugged in the IO-Headers and the front-usb 3.0 header (the bulky blue one).
After that it would not start up again, no fans were spinning but the mobo still had its lights on (this mobo has an error-code indicator on the back but its giving me no information)
I unplugged the usb header again but the motherboard still wouldn't boot. -> Screen stays black, nothing happening
I checked the Cmos-Battery and found out that it was empty, so i replaced it, but nothing changed.

I already tried to:
  • remove Ram sticks one by one and try them in another bay -> nothing changed
  • checked the PSU (paperclip-Test) -> PSU-Fan starts spinning, PSU seems to work
  • unplugged everything but the CPU + 24Pin Motherboard power connector -> nothing changed once again 🙁
im kind of at my wits' end

Anyone know what i could try next ?

Thanks in advance
 
This:

"unplugged everything but the CPU + 24Pin Motherboard power connector".

Any reason for not doing so? Could be that the connector is not fully or properly seated.

Also, did you mix and match PSU to motherboard cables from other PSUs?

Paperclip test is only a basic test. Do you have a multi-meter and know how to use it. Or know someone who does?

https://www.lifewire.com/how-to-manually-test-a-power-supply-with-a-multimeter-2626158

Not a full test because the PSU is not under load. However, any voltages out of spec are an indication that the PSU may be failing and/or faulty. Even if new.
 
This:

"unplugged everything but the CPU + 24Pin Motherboard power connector".

Any reason for not doing so? Could be that the connector is not fully or properly seated.

Also, did you mix and match PSU to motherboard cables from other PSUs?

Paperclip test is only a basic test. Do you have a multi-meter and know how to use it. Or know someone who does?

https://www.lifewire.com/how-to-manually-test-a-power-supply-with-a-multimeter-2626158

Not a full test because the PSU is not under load. However, any voltages out of spec are an indication that the PSU may be failing and/or faulty. Even if new.

So i got a multimeter from my neighbour, the 3.3v pins show 3.37v, the 12v pins show 12.7, i dont know what to trust more though, the psu or the multimeter 😅

I also assured that the psu power cable is fully seated, there is no gap and the clip makes an audible "click" when plugged in.

What i meant with "unplugged everything but the CPU + 24Pin Motherboard power connector", was that i tried to get the mobo to post wirhout anything attached.
 
Voltages appear ok if the multi-meter is trusted as being accurate. You would need to test other known voltages sources or use another multi-meter to validate your PSU tested voltages.

Power down, unplug, open the case.

Use a bright flashlight and even a magnifying glass to look for any signs of physical damage.

Bare conductor showing, melting insulation, browned or blackened components, kinked or pinched wires, shorts (metal touching metal especially around a plug or connector.

Especially around the IO-Headers and the front-usb 3.0 header. Could be short or failed connection there. Unplug and replug connections in that area. Ensure that connections are fully and firmly in place.

And, going back a bit: this mobo has an error-code indicator on the back.... what exactly is that indicator?

This motherboard?

https://dlcdnets.asus.com/pub/ASUS/..._IMPACT/E10809_MAXIMUS_VIII_IMPACT_UM_WEB.pdf

[Do verify that I found the correct User Manual.]

Start by checking the onboard Start and Reset buttons per Page 1-26.

Onboard LEDs (troubleshooting) are described on Page 1-27.

Q-codes are on Page 1-28.

What LED's are lit and what Q-code number do you see?

Review the entire User Manual to double check all of your work and configuration settings.
 
Voltages appear ok if the multi-meter is trusted as being accurate. You would need to test other known voltages sources or use another multi-meter to validate your PSU tested voltages.

Power down, unplug, open the case.

Use a bright flashlight and even a magnifying glass to look for any signs of physical damage.

Bare conductor showing, melting insulation, browned or blackened components, kinked or pinched wires, shorts (metal touching metal especially around a plug or connector.

Especially around the IO-Headers and the front-usb 3.0 header. Could be short or failed connection there. Unplug and replug connections in that area. Ensure that connections are fully and firmly in place.

And, going back a bit: this mobo has an error-code indicator on the back.... what exactly is that indicator?

This motherboard?

https://dlcdnets.asus.com/pub/ASUS/..._IMPACT/E10809_MAXIMUS_VIII_IMPACT_UM_WEB.pdf

[Do verify that I found the correct User Manual.]

Start by checking the onboard Start and Reset buttons per Page 1-26.

Onboard LEDs (troubleshooting) are described on Page 1-27.

Q-codes are on Page 1-28.

What LED's are lit and what Q-code number do you see?

Review the entire User Manual to double check all of your work and configuration settings.

Ok ill have to do the thorough checks you've described tomorrow.

In terms of leds and q-codes:
The three audio-jacks are lighting up and the clr-cmos button is lighting green.
The little screen with the q-codes stays off (does not show any codes or even lights up)

There are two buttons on the backside, one labeled "start" and one labeled "reset". Neither one seems to do anything.