Incomprehensible (for me) problems with the keyboard (ritmix)

I ran into trouble: both in games and in all sorts of Words, and indeed, when absolutely any key is pressed, the action does not take place constantly, but cyclically. That is, as if I were poking a button with an incredibly high frequency, and not holding it down. What kind of nonsense? I changed the response time in the control panel, it did not help, there is no fn key. The problem appeared after changing the power supply and RAM. Who knows please help