Are you connecting the HDMI display cable to the port on the motherboard or to the port on the graphics card?
If you’re currently connecting to the graphics card, I’d recommend switching that cable over to the motherboard and seeing if you get a picture on your monitor. If you do get a picture while connected to the motherboard, I’d recommend updating the graphics card’s driver.
Since you upgraded the processor, there may be an incompatibility of the current driver and the new processor. So you can temporarily get a picture by connecting directly to the motherboard to upgrade the driver and then revert to connecting HDMI to the graphics card."
