Question Monitor says no Video Input, mobo passes POST and everything powers on.

Dec 12, 2019
Hey guys. So I just finished a build, I will list the components. When I power everything on, the MOBO goes through POST and everything comes back clean as far as I can tell. All fans start up and what not. However, the monitor never receives a signal from the GPU. Even though the GPU passes the VGA POST test.

MOBO: MSI X570-A PRO Motherboard AMD AM4
CPU: AMD Ryzen 7 3800X 8-Core, 16-Thread Unlocked Desktop Processor with Wraith Prism LED Cooler
GPU: Asus TUF Gaming X3 AMD Radeon Rx 5700 Overclocked 8G GDDR6 HDMI DisplayPort Gaming Graphics Card (TUF 3-RX5700-O8G-GAMING)
PSU: CORSAIR RM Series, RM750, 750 Watt, 80+ Gold Certified, Fully Modular Power Supply, Microsoft Modern Standby
RAM: G.SKILL Trident Z Neo (For AMD Ryzen) Series 32GB (2 x 16GB) 288-Pin RGB DDR4 SDRAM DDR4 3600 (PC4 28800) Desktop Memory ...
Storage: Sabrent 1TB Rocket NVMe 4.0 Gen4 PCIe M.2 // Intel 660p Series M.2 2280 1TB PCIe NVMe 3.0 x4
Cooler: Corsair Hydro Series H100x Extreme Performance Liquid / Water CPU Cooler. 240mm
Case: Cooler Master MasterCase H500 ATX Mid-Tower

Things I've tried:
Re-seating components
Clearing CMOS
Running with out GPU
Running with out storage
Re-pinning the PSU plugs on both the PSU and the MOBO

Monitor works, I use it with my current (working) PC.
Everything I do I cannot get my computer to show me anything on the monitor, not BIOS, not anything. Part of me suspects it might be a bad PSU that is under performing? But I don't have an easy way to test this as the PSU I'm using for my working PC does not have enough CPU power pins to run the new build. Any help, suggestions, or references would be great.