[SOLVED] Need advice on a new build.

[PajamaSamurai]

I'll give my parts list first

Mobo: Asus Prime B450M-A
Graphics card: XFX Radeon RX 580
RAM: 2X8 Corsair Vengeance RGB Pro
CPU: Ryzen 7 2700X
PSU: Corsair CX750M


So, I'm building a PC for a friend. It's been a while since I started. It's been sitting mostly completed, covered, in my closet for a couple months. Pandemic and all that. I just got the SSDs I needed to finish it up a couple days ago. Today I got it all put together, plugged it in, turned it on, and it wouldn't post. I've built two other PCs and haven't run into this issue before. So I'm trying to find some guidance here.

A few things I've tried:

I took out the graphics card and the ssd, I'm not getting any beep codes. This leads me to assume the mobo is dead.

But I do have an orange light on the mobo, so I don't know if it's getting power in certain places and not others or what.

I'm using the dual 6 pin to 8 pin splitter to run into the graphics card, I don't know if thats necessary or not. It just seemed like I should use it. But I don't think I've ever used one before.

I took the heat sink off and checked the CPU. At first I was afraid that I forgot to put paste on the CPU, but it was just fine. No prongs were bent or anything. No paste in any sockets.

Everything turns on and runs. The heat sink fan runs, all the case fans run, the RAM is, at least getting power, and the light on the GPU is blue.

So I'm really stumped. I don't know where to start. I feel like replacing the mobo is probably a good place, but I want exhaust all my options before I make that investment. I don't know, you know. Maybe I'm missing a connection somewhere.

 

[tennis2]

Don't use a 2x6pin to 8 pin adapter for a GPU when your PSU has 6+2pin cables.

non-G suffix Ryzen CPUs don't have an IGP, so you're not going to get any display output to the ports attached to the mobo rear IO panel.

Have you tried a different display output from the RX580?