Not exactly sure what you mean. Might be helpful if you provide more info and what you have tried up until now.
Firstly are you sure it's charging? Connect to USB port for half an hour if you're not sure your mains charger is working.
Try holding both buttons for 10 seconds approx. If no joy - try again while connected to USB to your computer while iTunes is running.
If it's still not coming on, you're out of luck and need to take it to Apple.