PC Troubleshooting

1) The GPU fan may not spin if they don't need to (i.e., not hot enough to need cooling) 2) Why not get a Display Port to HDMI cable and try the port it is meant to use, then realize if the GPU can't initialize, you can't install Windows and boot. Do not use any video connectors from the motherboard; they will not work with a 3900X (that has no integrated graphics). 3) The GPU needs good power going to it; it needs to be well seated in the slot closest to the CPU; it may only output to the Display Port unless the manual says otherwise. See: https://community.microcenter.com/discussion/2818/tech-article-how-to-troubleshoot-a-newly-built-pc-that-will-not-post-boot-power-on

/r/buildapc Thread