Hello
If you are using android powered phone follow the instructions below
- Remove the battery.
- Connect to charger without the battery.
- Press and hold the power button for 15-20 seconds.
- Insert the battery (clean the battery contacts on both the phone and battery before).
- let it charge for at least 5 minutes.
If still nothing then it have to be hardware related issues' take it back to the store of purchase for warranty coverage or visit your local phone repair shop for service.