The monitor turns off for a couple of seconds, what should I do?

Question

Monitors

Good afternoon, who faced. Yesterday I noticed that the monitor turns into a black screen for a couple of seconds, without turning off, the red power lamp lights up, after clicking in the column .. i.e. click and black screen.. Could it be the built-in graphics card or the power supply? Can there be a click in the column or headphones when the monitor is not working properly? LG Flatron w2243S monitor, Intel G5400 processor, ASUS motherboard with built-in video card, bought a system unit a year ago, by the way, can the power supply still be like that? Thanks