Annoying monitor shit

[road doggy dogg]

So my mom's desktop, the monitor is playing this fun little game where it doesn't want to turn on now. Dunno what the deal is.

It's getting a signal, I know that much. Like under "normal" conditions, when the computer is off, the power button turns yellow. And when I unplug it from the computer, it does that (turns yellow). But right now while it's plugged in, the light is green, so it is obvs getting a signal from the computer. But the light is blinking green. Like a slow blink. Dunno what that means? And the screen is totally blank. Just started doing this yesterday as far as I know.

What could it be? Display drivers? Faulty monitor? I'm not sure where to begin to diagnose anything.
crossrine