Question My new motherboard isn't detecting my GPU

[doubleDF]

So, I wanted to upgrade my cpu from an i3 4360 to a Ryzen 5 2600. My old motherboard and ram was not compatible so i had to buy a new motherboard and ram too. I set everything up correctly and i get no video output. The motherboard i have(msi b450m pro-vdh max) has a light indicator that turns on if something is wrong, CPU/RAM/VGA/BOOT. The VGA light stays on and that light means it doesn't detect my gpu. The GPU I have is a nvidia gtx 980 ti. A friend lended me his 620W psu(just incase my 550W psu wasn't enough), an 8gb stick of ram, and an AMD R9 290. Ever since I've gotten the 620W psu i have been testing it with everything. When i put in the AMD R9 290 into my new motherboard, it works completely fine. But the thing is my 980 ti still works because i have tested it with my old motherboard and it still runs great.
I have tried updating bios, flashing bios, updating my gpu drivers. I don't understand why this is happening because it makes no sense. Everything individual part works but the motherboard just doesn't detect my working 980 ti. This is also my 2nd motherboard i previously bought the ASRock B450M-HDV R4.0 that I already returned thinking it was a faulty motherboard.

Old Specs
Intel i3 4360
Nvidia GeForce GTX 980 Ti 6GD5 V1
Corsair Vengeance 2x4gb 1600MHz
XFX Force TS Bronze Series 550W Power Supply Unit (80 Plus Bronze Certified)
biostar TB85

New Specs (what i plan to use)
Ryzen 5 2600 (New CPU)
Nvidia GeForce GTX 980 Ti 6GD5 V1 (doesn't boot w/ new motherboard
Aegis g.skill 2x8gb 3000MHz (new RAM)
XFX Force TS Bronze Series 550W Power Supply Unit (80 Plus Bronze Certified)
MSI B450M Pro-VDH MAX (new motherboard)

Specs from friend (to test every individual thing worked properly)
N/A
AMD R9 290 (boots up w/ my new motherboard)
Corsair Vengeance RGB Pro 1x8gb 3000MHz (not testing w/)
Cooler Master Silent Pro M 620W psu (currently testing w/ everything)
N/A

My main concern. My working motherboard doesn't detect my working Nvidia GeForce GTX 980 Ti 6GD5 V1 (along with every other spec that works and has been tested) but the AMD R9 290 does work with my new working motherboard.

I hope I gave enough information.

 

[Koekieezz]

Did you get your ryzen yet? im sorry but you didnt tell the chronology a bit clear. Maybe you could get someone motherboard with the same/near same series as what you got, make sure they have the cpu, and try to test it. also i recommend you to try MSi B450M Gaming Plus if you're planning to change, it got good vrm if you're trying to oc the system, well 2 ram slots only but hey it supports 3200mhz+

 

[JianweiTan]

have you tried using your friend's PSU with your 980Ti ? or did you previously OC'd your GPU? maybe 550w isn't enough to power it up, tune it to default profile and try again