Fully charge the battery of your phone. If your phone does not start charging, unplug the charging cable and plug it again into your phone. When fully charged, try to switch your phone on.
Íf your phone is still dead, please see the repair options at your local Nokia support pages.
It is possible to fix many phone problems yourself in a few minutes – including phone freezes or does not switch on, application crashes, sound problems and a blank display. To save yourself time, try these three fixes.
1. Restart your phone
If the phone hardware is jammed, you should first try restart your phone. This does not reset the Microsoft Account (Windows Live ID) or remove any consumer data.
Option 1: To perform the power reset for phones with integrated battery (phone has a special electronic circuit which switches off the power when the key combination is pressed):
Option 2: To perform power reset for phones with removable battery:
2. Update the software
You might not be using the most recent software for your phone. Updating to the latest version of your phone may resolve your issue.
You can check for the availability of Lumia software updates in your region here.
3. Reset your phone
Warning: This erases all the personal content in the phone, including apps that have been purchased and downloaded (may be re-downloaded again), and restores the factory settings.
To reset your phone to the state in which the phone was in the first time you turned it on, go to Settings > About and then Reset your phone.
If you lose your phone, you can reset your phone remotely. In this option you need have the Find My Phone feature enabled and your phone must be connected to mobile network.
1. Login to http://www.windowsphone.com.
2. Click on the drop down menu right next to your name, and select the device that you would like to erase.
3. At the top left corner, you will see the name and model of the Windows Phone.
4. Click on Erase your phone.
Press and hold the Volume Down key and Power key simultaneously until you will feel vibration. The phone will reset and boot up automatically. Note that this does not reset your Microsoft (Windows Live) Account or remove any of your data.
If your phone still does not respond, remove the SIM card and try again.
When the phone switches on, confirm that it has the latest software version by going to Settings > Phone update, and then tap Check for updates.