Starts for a split second, fans wroking, light on but then stops

Anytime I press the power button on the tower it starts for a split second, fans wroking, light on but then stops, tries again and again until I let go off the button. The monitors are on but with no power they are blank. It reminds me of a car trying to start up and failing. Its been like this all day when I tried to open apps this morning it wouldn't let me do anything, not even ctrl+alt+del. The only thing it would let me do is use Discord (Skype for gamers) and talk to my friend. If it helps its a HP windows 10 with 2 monitors