Monitor problem, how to solve

Hello, there is a ViewSonic monitor, just yesterday it started to go out just like that, at first it flickered and went out, then it just quickly started to go out. The indicator on the monitor shows that there is a signal from the video card, but the image disappears, it only helps to turn the monitor off and on, but the image appears for 5 seconds. When the monitor cools down, it can work for an hour, then turn off again. There are 2 video card connectors on the video card, the same effect is observed on both, I also checked it by connecting to a laptop, it also works for a while and goes out. Is this normal? Why didn't he die immediately then?