In order to fix the problem, I recommend you make sure that the battery of the device is charged. If the battery is charged, I recommend you reset the phone to its factory condition. For this purpose, navigate to Menu > Settings > Phone > Phone management > Factory settings and select the Delete data and restore option. Alternatively, you can press the
* + 3 + call + Power on combination, but for this method you will need to input the lock code. The default one is 12345.