Can't mine with third card

I am using the ASRock Z490 Phantom Gaming 4 ATX Intel Z490 DDR4 S1200
Intel Celeron, 8 GB Ram in one Slot.

Using one RTX 3080 works fine.
Adding a second one works a well.

When I add a third card I get

and can only use one card for mining.

Switching back to two cards gives me a hard time to get the second card working. Need to reset the BIOS and make the settings again. But it is kind of a non reproducable process to make two cards work.

Tried to use other PCIE Slots on the board. No Luck.
Running on 2 PSU.

Help is appreciated

I tried an older mainboard and everything works as except. Event with a 4th card.
So there must be an issue with the mainboard or the hardware configuration on it although everything is brandnew…

I have the Z 490 Phantom gaming 4/AC card also and every time I try to plug more than 2 card into the motherboard it fails out. I’ve tried using risers, no risers… I’ve tried every single one of the PCIE ports and nI can get 2 cards to work in any of the PCIe ports, but when add the third it only boots into bios…
spent 4 to 6 hours with bios settings and different variations but no dice!!! I’m going to try a pcie card to 4 usbs in 16z pcie and see if that works when it comes in on 28. If anyone is out there differently feel like tried everything besides getting new motherboard… any help on this thread would be greatly appreciated. thank!

Yeah I tried a lot without any luck. But did not try a 4-to-1 riser card. Hopefully it works out for you.
After it worked perfectly with an old atx board I ordered a asus tuf board with the 490 chipset and 1200 cpu socket for my celeron. Should arrive today or tomorrow.

I am having the exact same issue.

very frustrating.

let me know if you make any headway on this

thanks

Worked immediately with another mainboard.
Using the Asus TUF H470 Pro now.

did you just return the asrock board?

yes of course