Hi everyone,

I'm hoping someone can point me in the right direction because I've reached the point where I'm running out of ideas.

Specs

• CPU: AMD Ryzen 7 9800X3D
• Motherboard (original): Gigabyte B850 Eagle WiFi 7
• Motherboard (replacement): Gigabyte X870E AORUS Stealth ICE
• PSU: Thermaltake Tough Power 1000W
• Cooler: Corsair Titan 360mm AIO

On my first motherboard, when I switched the PSU on, all the lights would flash for about half a second. After that, pressing the case power button or jumping the power pins did absolutely nothing.

I removed the board from the case and breadboarded it on the motherboard box. Same result.

I also verified the PSU by running the paperclip test and installing it in another PC where it powered the system successfully.

One strange thing I noticed was that if I removed the RAM, the DRAM debug LED would illuminate. Reinstalling the RAM made the DRAM LED go away, but the board still wouldn't power on.

I thought this was the mother board so I got a replacement.

I installed a brand-new Gigabyte X870E AORUS Stealth ICE.

The system has the exact same symptoms:

• When I switch the PSU on, the lights flash for about half a second.
• Pressing the onboard power button does absolutely nothing.
• No debug LEDs come on.
• The debug display stays blank.

If I press the Q-Flash Plus button (without a USB drive installed), the fans spin up, the RAM RGB lights for about one second, and then everything shuts off again.

So far this is what I've gotten - 

• PSU works in another PC.
• Using the original PSU cables.
• 24-pin ATX connected.
• CPU EPS power connected.
• Tried jumping power pins on the original board.
• Tried onboard power button on the new board.
• Two different motherboards with identical symptoms.

I'm genuinely at a loss here. 

Any advice would be greatly appreciated. Thanks!