Notebook Hardware and Upgrade Questions

I just bought spectre x360, 2 days ago, and I heard a constat buzzing after shutdown computer completely which comes from bottom air intake close to "delete" button. When I turn-on X360, the buzzing is stronger; normally it is not possible to understand a noise while you work, however it is really weird that there is a buzzing noise,  even after shutdown completely. I contacted with HP service, however they said there is no any record for similar things and they said the buzzing is normal.

I should say this is not good, I checked some forums and saw some records related HD520 Intel. And it is obvious there is no any solution. However, my problem is more, buzzing noise goes on after shutdown. I made some minor test, I insert a USB and the buzzing was more noisy, after takei it out buzzing niose was minor however still. 

My question, what should I do? Isn't it weird that you turn off your computer and get on a plane and your computer is still active! Or it consume battery life while you sleep? Or isn't clear that there is a problem with this computer?

 I hope someone from HP answers me, because service thinks it is OK!