Dead Gigabyte Z490 Aorus Pro AX (How to know for sure?)

[Arkon3]

I have a machine 18 months old with a Gigabyte Z490 Aorus Pro AX, been working fine for all that time. Yesterday went to switch it on and it's as dead as a dodo. No fans, lights, sounds, nothing. Also the PSU doesn't fire up either. I took it all apart, removed everything and have just the MB on the bench with the PSU.
If I unplug the PSU from the board I can kickstart the PSU by shorting pins 4 & 5 on the big connector. The PSU fan fires up and when I test all the line voltages on the plug they are all correct.
Also tried with another working PSU and still nothing so it's not the PSU, or the Power switch on the case.

I've tried the removing cmos battery trick and clearing cmos, and that had no result. Any clues anyone might have? What would cause the fairly new MB to not turn on the PSU when shorting the Front panel header Power switch pins? Also I read a lot about RMA'ing the motherboard. Do I do that with the company I bought the board from or Gigabyte themselves?

Thanks all in advance for any insights.

 

[hititnquitit]

Youll have to contact gigabyte unless you purchased an extended warranty from the store.

 

[Denpepe]

You can always take your machine to a pc store to have it tested if you do not have spare parts.

Last time something like what you are describing happened to me it was a dead CPU.

 

[Furious_Styles]

You want to RMA through Gigabyte. Just use their website and describe what happened you should be quickly approved to return it for service. Expect 2-3 weeks total turnaround time.

 

[kirbyrj]

You want to RMA through Gigabyte. Just use their website and describe what happened you should be quickly approved to return it for service. Expect 2-3 weeks total turnaround time.

This is what I'd do. I doubt the store would warranty that 18 months after purchase unless you bought a warranty plan from them.

The fact that the OP ruled out the power supply seems to indicate it's the motherboard. When I've had similar issues, it's always been the motherboard for me.

As to why it happened? Realistically, anything could have happened. I've had similar cases where I just have no idea why it stopped working but it was definitely the motherboard after checking every other component.