Dell Latitude 7300 flickering

Hello all, my Dell Latitude 7300 is flickering like crazy. The wierd thing is, the only thing that works is the Dell screen test mode on boot, nothing else works. Not the Dell logo, not the BIOS, not windows. But the screen test theoretically proves its not a hardware issue, right? I've tried cleaning and reseating the cable. I've also tried new drivers, screen firmware, BIOS, changed the hz, turned off the Intel variable refresh rate settings, and now I'm resetting windows to see if it does anything. Any ideas? TIA