So, when you press the power button, there are no noises from the laptop and the screen remains black, right? Please disconnect the battery and the power cable and hold the power button for 20 seconds. Reconnect the cable and try to boot again. If the problem persists and the laptop is under warranty, please contact the seller and ask for guidance. If you have been using the PC for some time, the cooling fan may be covered with dust which may prevent its normal functionality. As xpcman suggested, you should ask for assistance from a professional.
Hope this helps