Ender 3 V2 Screen problem

This printer has been working just fine. Yesterday, I turned the print off after printing for 3 or 4 hours. Everything was OK at that time. Today, I turned the printer on and the display screen remains blank except for a dark gray background and nothing else on the screen. Does anyone have an idea about what is causing the problem? Am I looking that the possibility of buying a new main board. Or perhaps a new screen. There is power going to the screen display because it displays a gray background.

I would start by measuring the Power Supply voltage.
Then would move to see if your computer could make a connection to the controller via USB..
The display is not needed to print via a USB connection from some slicers.

Then if you can still print you may only need to trouble shoot the display and or the display connections.

When you say grey...do you mean the dull grey during a firmware upload?

Did you have a micro sd in your printer with a .bin file on it? If you have a .bin file with the same name as the firmware currently uploaded, the system stalls out

Along the line of what robert_clif said, you should connect your printer to a computer via something like pronterface to see if it can take in commands, then you can figure out if it's your display or the board that's an issue

If it IS your display, flash that with new firmware (UI has their own firmware) before buying a new one as a last ditch effort to save it.