Hi, thank you for contacting JustAnswer.com. My name is Russell. I will do my best to provide the right answer to your question.
(1) Where are you plugging it in, please?
(2) Can it turn On when not plugged in, when running only on battery?
(3) If it turned On before, then was it running on battery then, and was it running for long enough to run down the battery?
If (1) is 'a power adapter', and if (2) is or was 'yes', then you may need to double-check your power adapter, whether it is dirty, whether it is the correct one, etc.
But tell me more about it - I may have guessed wrong - and I will offer further advice.
One thing is sure... if any part of a new system is genuinely defective, the warranty will cover it.