Turn off your Samsung Galaxy J7 completely. Then you have to press the following keys to turn the phone on again: " Power On/ Off "," Volume + " "Home" button . If the Samsung Galaxy J7 vibrates once, release the power on/ off button but keep the other two keys from the key combination pressed until a small menu appears on the screen. Now mark the entry "Wipe cache partition" with the volume down key. With the power on / off button the entry can be selected selected and the process gets started. This usually takes only a few seconds. Then the previously displayed menu appears again. Now select the first entry with "Reboot system now" and run the command again with a press of the power button. Your Samsung Galaxy J7 will now reboot. That's it. The reboot can now might take a few seconds longer. After that no more errors such as overheating, black or flickering screen or battery drain should occur with you phone