The Apple iPhone 11 utilizes an LCD panel in its design, which means that a high voltage backlight circuit is an integral part of the design to make image on the display visible. Damage to this circuit most often occurs during a screen replacement in which proper precautions are not
taken, particularly if the battery is left plugged in when the screen is removed or connected to the logic board of the device. There is a chance that if the battery is left plugged in, a resistor on the logic board will be damaged, causing the backlight circuit to malfunction.