Why won't my HTC One X Plus turn on?

[AC Question]

my htc one x plus wount turn on...

hi i am using an htc one x + pm63100 64gig using android 4.2.2... it was charged up to 80% i was downloading on 4g then it suddenly went off and could not turn on, i have tried holding the power button and volume down button for 15sec and it did not charge or turn on, i av tried charging over night thinking if it was a battery drain and it did not turn on, please i need a solution