Question PC won’t boot with new GPU

[CompSciDude]

HELP!!!
I just upgraded my GPU from an asus 4gb radeon rx560 to an XFX radeon 16gb 6800. When i try to boot with the new gpu, there is absolutely no response except for the fact that my keyboard lights up. when i switch back to my old gpu, it boots just fine.
SPECS:
cpu - extend 7 2700x 8 cores 16 threads
(old) gpu- 4gb radeon rx560
(new) gpu - 16gb radeon 6800
ram - 16gb ddr4 corsair vengeance
ssd - 500gb samsung
psu - 750w corsair cx750m

 

[CompSciDude]

my mobo is a gigabyte x570 gaming x

 

[Nemesia]

CPU and case fan spinning? GPU fan spinning for a few seconds at system start?

 

[CompSciDude]

CPU and case fan spinning? GPU fan spinning for a few seconds at system start?

when i try to use the new gpu, there is no response including all fans

 

[Nemesia]

when i try to use the new gpu, there is no response including all fans

You properly connected all the GPU power connectors using the PCIe 6+2 cables?

 

[CompSciDude]

i connected the two dedicated 8 pins as it said

 

[CompSciDude]

You properly connected all the GPU power connectors using the PCIe 6+2 cables?

i connected the two dedicated 8 pins. could it be a software or driver issue?

 

[Nemesia]

Make sure both are plugged in correctly. Sometime they are not. Saw that like a few hours ago in another thread.

You are using the PCIe 6+2 cables right and not any 4+4 cable?

 

[CompSciDude]

Make sure both are plugged in correctly. Sometime they are not. Saw that like a few hours ago in another thread.

You are using the PCIe 6+2 cables right and not any 4+4 cable?

is there a way to tell the difference with corsair stock psu cables?

 

[CompSciDude]

Make sure both are plugged in correctly. Sometime they are not. Saw that like a few hours ago in another thread.

You are using the PCIe 6+2 cables right and not any 4+4 cable?

just confirmed I am in fact plugging it into the 6+2 pcie port and it still won’t work.

 

[GabrielV]

Load default settings in bios and try again

 

[popatim]

It could be a UEFI detecting changed hardware and blocking Boot.
Enter the bios and disable Secure boot. I would suggest saving the current settings in case something goes wrong you'll be able to reload them and still boot with the old card.