Question PC stuck in a boot loop when GPU is connected

Feb 26, 2020
I just bought new cpu,mbo and ram and assembled it along with my previous power supply and gpu. When I turned the pc on the rgb on the mbo,ram and cpu and all the fans were on but I had no signal on the monitor. Also,pc keept restarting(fans and rgb kept turning on and off) every 3-4 sec. I took my ram out and turned it on,it started restaring every 15 sec now,then I took the gpu out,same story.

Then I took the gpu out and pc ran fine,not bootloops. I did manage to get into bios and version was 2.9 I think and when I tried to run win 10 of my ssd it got to the login screen and stayed there fot like half a sec and then restarted. Then I plugged in a usb with ubuntu on it,similar situation; it managed to get to the part where ubuntu starts loading and then it restarted again.

That was yesterday,today nothing works and I can't get the picture. Same situation - when gpu is plugged in it restarts every 3-4 sec. I tested the gpu in the other pc and it works fine. Xmp is not enabled if thats important here. So I don't know what the problem is,is the power supply which works fine too on the other pc,or is it mbo or ram or cpu?

I cleared cmos(removed battery),reinstalled cpu, checked all of the connections,there are no shorts because it did got to bios when it was in the case. I did not flash any bios because it us supposed to be 2nd gen ryzen ready out of the box.

I wanted to try running the memtest86 but I cant get any signal on the screen so I cant check any error messages that appear.

Also did check different memory slots and one ram stick at a time.
Cpu: Ryzen 2700x
Mbo: Asrock Steel Legend B450
Ram: Kingston HyperX Fury 3200 mhz 2x8gb
Power supply: Thermaltake TR2 Bronze 450 W
Gpu: Saphhire Radeon RX560