u/Background_Town2624

Hey everyone, I’ve been troubleshooting my PC for a full day and I’m stuck. Here’s everything I know:
My specs:
• Motherboard: MSI B450 Gaming Pro Carbon AC
• CPU: AMD Ryzen 7 2700X
• GPU: Gigabyte AORUS RTX 3070 Master (brand new to me, verified working)
• PSU: MSI MAG A750GL 750W (brand new)
• RAM: G.Skill Trident Z 2x8GB
The problem:
VGA debug LED is permanently on. No signal to monitor, keyboard and mouse don’t get power.
What I’ve tried:
• Reseated GPU in both PCIe slots
• Replaced GPU entirely with verified working RTX 3070
• Replaced PSU with brand new 750W unit using new cables
• CMOS reset multiple times (battery removal and JBAT1)
• Reseated RAM in correct slots (A2 and B2)
• Tested old RTX 2060 in friend’s PC and it shows up in Task Manager
•. I placed only 1 stick of RAM
Thinking:
I updated my BIOS about a month ago. Shortly after I started getting FPS drops in Valorant. Then the PC completely stopped outputting video.
With RAM installed: VGA LED lights up
I believe the BIOS update may have caused this. I’m about to try the BIOS Flashback button with a previous BIOS version. Has anyone experienced this or have any other suggestions?​​​​​​​​​​​​​​​​