Why is the computer not sending a signal to the monitor?

Question

Iron

In general, a month ago I turned off the computer (from the Start menu). The next time I turned it on, the computer turned on, but did not give a signal to the monitor. I thought because of the monitor, I replaced it with a friend's monitor, the same garbage (besides, my monitor on another computer turns on). Then I thought the video card burned out, switched to the built-in one, the same problem. Then I replaced the VGA cable, but everything remained the same.
In addition, I noticed that now, when the computer itself turns on, it is impossible to turn it off with the power button. To turn off the computer, you need to press and hold, but what should I do, because the signal does not go to the monitor. As I understand it, the problem is in the system unit.
PS Sorry for the spelling.

Answer 1

Yes, it is clear that the reason is in the system unit, in your case it needs to be taken to a repair shop or invite a specialist to your house.
If you want to learn on your own, which is difficult and sometimes expensive, then read about methods for diagnosing computer problems , look for a manual for your motherboard and BIOS (beeps about errors, even if the BIOS is not visible), etc.

Answer 2

How many sticks of memory are in a PC?
Try to run with one stick of memory.