In [https://guideusermanual.com/product-name-xperia-z4-tablet-manual&po=608458&lang=English|Sony Xperia Z4 Manual] following steps are written to troubleshoot screen problem.
* Remove the back cover of your android device and reset the battery to make sure that the contacts are touching properly, and the phone is getting power. Then charge your phone and leave it for charging for few hours.
* If the first step fails to solve Android Black Screen Of Death issue, then take out the sim card, SD-card and battery from the phone and leave them for 5-10 seconds. Put the battery and charge it.
* If the previous step also fails, the hardware factory reset will be the last step to perform. This process will erase all the data on your android phone, but you will not be able to backup them because of the Android Black Screen Of Death. Make your phone ready for hardware factory reset by resetting the battery and taking the SD care out. You can keep the sim card in your device and close the phone.
* Now put the phone into charge to avoid any distraction in the factory reset process.
* Press and hold the Volume up, Power and Home keys to boot the phone in recovery mode. In the recovery mode, select Factory reset/ Wipe data using volume keys. Press Power key to start the hardware factory reset.