thanks for the answers. I managed pressing the power button for almost a minute without the power cable plugged in. Once I plugged in the cable and pushed again the power button the laptop finally turned on. Thanks again for your time to answer and have a great new year!  
Good morning to everybody. Yesterday evening i've unpacked my brand new XPS 9520 but...it doesn't turn on. No life signs of any kind, pushing the power button makes nothing. I thought that maybe the battery was empty, so i let it charged all the night...but actually the battery led on the laptop was always blank. It looks like the laptop it's totally dead. Am I missing something? Or is it damaged and i need to make a return? thanks in advance
brand new laptot doesn't turn on