What causes noise on the monitor?

Question

Monitors

Good day, dear friends. My problem is that the monitor does not display an image. Briefly about the main thing: the computer has been working quite stably for 8 years. Only a year ago I rearranged the power supply, because the cooler stopped working, after that everything worked fine again. Yesterday I watched a movie and suddenly there were strange noises on the monitor, it looks like flickering. A minute later, the monitor turned off and I waited a bit, turned off the computer from the power supply. Then I turned it on again and something strange started: the computer started to load quickly, and after the "greetings", the monitor turns off and does not display an image. I repeated it again and again, but the result is the same: the computer loads abnormally quickly and then goes out. Has anyone had to deal with this? I will be grateful for your help.

Answer 1

Most likely overheating of the video card, as written above. Try replacing the thermal paste.

Answer 2

For some reason, everyone assumed that the video card is discrete. What if it's built in? Then you can't change the thermal paste. In general, there is little information. If possible, answer the following questions:
1. Is the video card discrete or built-in?
2. How does it behave in safe mode?
3. Monitor or cable tried to change?
If the monitor and cable are in order and the video card is built-in, then the best way out is to buy a simple discrete video card and not fool around with repairs.

Answer 3

And the monitor's power supply can die and just by the time the system starts, it goes into defense.