Want to Confirm I have Defective Motherboard

Fruhstuck

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Nov 28, 2012
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Hello All,

I'm in the process of building a new PC and I believe that I may have a defective motherboard. I've never had a defective motherboard before. So this post is mostly to confirm my suspicion or see if anyone has a suggestion to what I have missed. I will post my system specs at the bottom of this post. Any who, here's my story.

My system simply is not getting power. The symptom it is displaying is that when I go to flip the PSU power switch to the on position, the motherboard will have its LED lights turn on for a split second and then turn off. No fans spin, no system speaker beeps, no lights on the motherboard or any other activity show. May be worth noting that no other LED lights on the system outside of the motherboard itself turn on.

I have tried many troubleshooting methods to attempt a fix on this and will list them here:

- Checked to see if PSU is faulty by swapping out with an equivalent 750 wattage PSU, . Equivalent confirmed working because used in another stable system.
- Removed GPU and ran system without. Confirmed GPU works by using in another stable system.
- Removed ram down to one stick and used in different ram slots. Confirmed proper ram is being used by referencing manufacturer's acceptable ram chart.
- Check CPU for bent or broken pins, re-seated CPU, made sure thermal paste properly applied.
- Used different CPU and PCI-E power cables to confirm cable not faulty. Checked for bent or damaged power pins.
- Removed entire motherboard from case and placed on ESD safe backing. Ran only CPU, CPU cooler, and one stick of ram outside of case to see if shorting occurred from case mounting pins or case.
- System has 8 pin and 4 pin CPU power options. Attempted running different variations of CPU power connections.
- Reset CMOS
- Used multi-meter to confirm motherboard battery voltage was correct at 3v.
- Confirmed all wires are properly connected to motherboard and components.

System Specs:

PSU - EVGA SuperNOVA 750 G3 Model 220-G3-0750-X1
RAM - CORSAIR Vengeance RGB DRAM 16GB (2 x 8GB) Model CMR16GX4M2C3000C15
GPU - GIGABYTE GeForce GTX 1070 Model GV-N1070G1 GAMING-8GD R2
CPU - I7-8700k Model BX80684I78700K
CPU Cooler - EVGA CLC 240 Liquid / Water CPU Cooler Model 400-hy-cl24-v1
Motherboard - GIGABYTE Z390 AORUS PRO LGA 1151 (300 Series) Model Z390 AORUS PRO
SSD - SAMSUNG 860 EVO Series 2.5" 1TB Model MZ-76E1T0B/AM

That's all I got. Any feedback is appreciated.

Thank you

 
"System has 8 pin and 4 pin CPU power options"

These are not options, both need to be connected. It may be possible to use a P4 power connector in the 8-pin ATX 12V 2x4 using pins 1,2,5,6 instead of an 8-pin connector.

Since the power supply has two 8pin (4+4) connectors, you should use one 4+4 in the 8-pin connector and split the other 4+4 connector to use just the 4 pin in the other connector.
 

Fruhstuck

Honorable
Nov 28, 2012
54
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10,630


I tried that and shows the same symptom :/