Do you have lot of apps in your mobile? Sometimes you download apps and you don't use it. Then you forget to uninstall the app. Like that your phone screen will be full of apps and even you will not able to identify which app you need and which app not.
 
 Now you can quickly uninstall the apps you don't need. So all you need to do is go to the main screen. In the top of the right corner you can see vertical line with dots. That indicates the menu bar. First you need to click on that menu bar. Then there is an option call uninstall. So, you need to select that uninstall. Now you can select all the apps you need to uninstall.
 
 You can click on uninstall to delete the apps and uninstall the apps. This way you can uninstall multiple apps with one click.

1.Turn off the phone
2.Remove battery,sd card and sim card
3.Press the power button for two minute to drain off the remaining power PS;should not be connected to the charger as well
4.Replace the battery then start the phone,if this doesn't work repeat the process
5.If the screen still does not go on,use a set of screws to open the back cover to access the motherboard
6.Identify the screen connection to the motherboard on the side.remove it and then replace it
7.Place back the battery then turn on the screen should come back on
8.If this doesn't  work the screen has to be replaced
this link step by step helped me https://www.youtube.com/watch?v=vTOuw_MKUbU and i have also attached images of how the phone should look like when opened up.