Screen black after PC startup?

My PC with Windows 10 suddenly hung up for no reason. Everything stopped, only the sound of a YouTube video went. So I only had the off button. Now (2 days later) still nothing works. Cable in and out again, PC sucked, password entered blindly etc. In addition, the PC turns off by itself if I press a few times on the spacebar. The screen is simply black and the login window does not come. Is there just a reset or are there other options? It is not on the screen or the power strip, all other devices (LED, PS4, speakers) are working properly.

First check if the monitor works (other PC or laptop / mobile phone) and if this goes check the video card (workshop).