Need help for troubleshooting

[RedEdain]

Hi guys! 

 

I just got my RX 570 from Gigabyte (Gaming OC), and I installed it and powered up the system. First try, the screen detects something but nothing happened. Blank screen. The GPU's RGB LEDs are working though, just like the fans. I try a second time, and surprise! It displays something. Since I have an old (2012-2014) motherboard, it showed me the Intel screen, where post codes are shown, and only one, 5A, is showing. I tried the BIOS, but everything seemed to be frozen. What could be happening?

 

M-Board: Intel DQ35JO

CPU: Intel Core 2 Quad Q9400

GPU: Gigabyte Radeon RX 570 Gaming OC

PSU: EVGA 450 80 PLUS BRONZE

 

Also, since the drivers are coming in a CD (What a wonderful idea.) I didn't installed them. Could it be the problem? Thanks guys!

 

P.S. I also included a short video of what it does.

[RedEdain]

Just a little precision, the 5A postcode also appeared with my last gpu, a MSI GT 710.