Question New pc won't boot once the gpu is plugged in. What do I do?

[Balzacchi]

So I just finished this new build, it boots fine without the gpu installed but once I get it on there I no longer have a video output. Plug it out and it boots fine again. I have tested the gpu on another pc and it seems to be working fine.

Specs
CPU AMD ATHLON 3000G
MOBO ASROCK STEEL LEGEND B450M
RAM 8GB BALLISTIX DDR4
PSU XPG CORE FACTOR 650W
GPU ZOTAC RTX 3060TI

Any ideas of what could be happening?

 

[Newtonius]

Are you 100% sure you're plugging the video cable into the GPU video port and NOT in the motherboard video port?

 

[Balzacchi]

Are you 100% sure you're plugging the video cable into the GPU video port and NOT in the motherboard video port?

Yes. I tried both.

 

[Dark Lord of Tech]

Is booting from the GPU enabled in the BIOS and what version is the BIOS at. Current?

 

[Balzacchi]

Is booting from the GPU enabled in the BIOS and what version is the BIOS at. Current?

Even if booting from the gpu is turned off it should still show video if I plug in directly to the motherboard, shouldn't it?
As far as the bios go I didn't update it or anything so it should be at factory settings.
Can an outdates bios be causing this problem?

 

[Newtonius]

Even if booting from the gpu is turned off it should still show video if I plug in directly to the motherboard, shouldn't it?
As far as the bios go I didn't update it or anything so it should be at factory settings.
Can an outdates bios be causing this problem?

Well it could be that your BIOS is set to only use the integrated graphics and not your GPU, in your BIOS go to 'Advanced' > 'AMD PBS > "Primary video adaptor" and set this to "PEG", as shown in your manual here on pg 77. If it's on PCI then that means it's using your integrated GPU (your CPU). I would recommend updating your BIOS first before doing all this since updating BIOS will revert all changes. You can find your BIOS versions here but please read the descriptions first before proceeding as some versions require a previous version is installed beforehand.
If none of this works, then you probably got a bad motherboard.

 

[Balzacchi]

Well it could be that your BIOS is set to only use the integrated graphics and not your GPU, in your BIOS go to 'Advanced' > 'AMD PBS > "Primary video adaptor" and set this to "PEG", as shown in your manual here on pg 77. If it's on PCI then that means it's using your integrated GPU (your CPU). I would recommend updating your BIOS first before doing all this since updating BIOS will revert all changes. You can find your BIOS versions here but please read the descriptions first before proceeding as some versions require a previous version is installed beforehand.
If none of this works, then you probably got a bad motherboard.

Will do all that.
Thank you so much for the help, I really apreciate it.