|I will say that intel onbard graphics have gotten better over the years|
Nope, AMD IGP have gotten better over the years.
U can't update video card firmware with blank screen, u need video card working.
Using onboard graphics enter BIOS and set initial display to PCIe x16 save settings and try the video card. Do u have older video card u can try? Are u sure hd 5750 is working? Did u connect 6 pin pcie(75w) cable to the video card?
We can not fight new wars with old weapons, let he who desires peace prepare for war - PROPHET.