Dead screen or Graphics card?

I have an MSI GL62. I can hear the laptop boot up but I can't see anything on the screen. When I plug an HDMI cable in, I hear the laptop beep to let you know it is connected to a device, but nothing is showing up on the external monitor. What is the best way to test if it is just the graphics card or if it is just the screen? Should the HDMI work even if the screen is cracked?