2 new exact same GPUs, one doesnt work.

[Mate_6]

I have 2 ASUS RX470s, as the title says...

I put one in the Pciex16, system boots,I change it to the other one, system doesnt boot,the light on the gpu is blinking rapidly.

At my FIRST use I tried starting my pc with both,one in the pciex16,one in a pciex1-16 riser.
There was a little burning smell I didnt know from where but probably from the gpu thats not working now.

Pcie riser is not the culptrit, I tried it with an older gpu and the system booted.
PSU: Rorsair RM850x


Is it burned now to wreck?
I bought it a few days ago should I send it back,or is it fixable?

 

[Herc08]

Are you wanting to do cross fire, or did you just get two as a back up?

 

[Mate_6]

I bought them to mine ethereum or other cryptos, you dont need to crossfire them for that.

 

[McDuncun]

Technically yes but if the board does not support it then it`s not going to help either way, have you used both GOU`s in both PCi ports?

 

[Mate_6]

I take out the working one,replace it with the not working one, same pciex16 slot ,same psu cable, same hdmi cable.
and its not booting.

 

[Mate_6]

MERGED QUESTION
Question from Mate_6 : "Motherboard doesnt boot with more than one GPUs."

mobo has 5 pciex slots,it boots with one GPU hooked up but not with two.
PSU is not the problem.
What could be the case? Upgrade BIOS?Delete CMOS?
Im just guessing here.