Xps l502x randomly goes to sleep mode

My xps l502x started acting up yesterday even though I turned it off after use the day before. It randomly gets into sleep mode when I'm using it also while booting. The first time it happened I turned it long pressing the power button, but it won't come up when I tried to turn it on again the indicator light behind the power button only flickers and finally off.

After a few minutes it finally came up, but the sleep problem still persists. 

Someone should please help as this is becoming frustrating. Thanks