The digitizer is a crucial component of a touchscreen device, responsible for translating touch actions into digital signals that the device can interpret. If a hard reset does not resolve the touchscreen's unresponsiveness, it's likely that the digitizer is damaged. Physical damage, such as cracks or heavy impacts, can impair the digitizer's ability to function correctly, leading to an unresponsive touchscreen. This type of hardware issue requires professional repair or replacement of the touchscreen assembly to restore functionality.