Question New Gigabyte 3090 Aorus Waterforce Extreme is not powering up, I get flashing white LEDs by the power connector


Apr 19, 2001
I replaced my current 780ti with the 3090 and am having all kinds of issues trying to get it to work. The system wont boot up and there are flashing white leds where the two 8 pin connectors from the PSU plug in.
I have an EVGA Supernova G2 1300W PSU and the motherboard is an ASUS MAZIMUS Formula VI LGA 1150 board.
The motherboard has the auxiliary 4 pin and 6 pin power connected.
The computer runs fine with the GTX 780Ti but nothing with the new 3090. I am stumped what to check next

This is what I see when powering on


The white LEDs make me think it's the psu.
Ampere has a particular problem with transient power delivery that prompted manufacturers to include warning LEDs at the gpu PCIe slots to light up when the psu is detected to not be up to par.
Though the Supernova G2 should be fine, how old is it? They all degrade with age.

I noticed the 24pin cable and reservoir completely obstructed the motherboard's Q-LEDs. They can be really vague at times, and not be of much help anyway.
Still wanted to point it out just in case.

During the video, I saw the following POST codes - posting them in case anyone notices anything else:
15: Pre-memory System Agent initialization is started
64: CPU DXE initialization is started
A2: IDE Detect
AE: Legacy Boot event
Last one was either A0 or AD:
IDE initialization is started
Ready To Boot event

If I read the post codes right, the card could also not be responding because it requires bios to be run in UEFI mode, and you're still in Legacy mode.
It's pretty easy to check, but you might need to remove the gpu from the equation so you can get into Windows via the cpu's iGPU, and check System Information.
If you already know the current bios mode, then this step can be skipped.

Short version: suspected psu aging, or motherboard bios not running in UEFI mode.


Check your PSU cables to make sure they are plugged in correctly and fully. According to Gigabyte's website, the white flashing lights are an indicator of a power supply abnormality. Your PSU is plenty strong enough so maybe the cables aren't fully seated in the GPU or PSU.