How can digitizer failure be initially tested?

To initially test digitizer failure, opening the camera app and dragging focus across the screen is a practical approach. This method checks the responsiveness of the touchscreen. When dragging the focus, the screen's ability to register touch inputs is assessed; if the digitizer is functioning correctly, it should respond smoothly to these inputs.

In contrast, checking for wireless connectivity, taking a screenshot, or measuring battery voltage may not provide insight into the digitizer's functionality. Wireless connectivity relates to network capabilities, a screenshot assesses the display rather than touch sensitivity, and battery voltage measurement pertains to the power supply rather than touch input response. Therefore, actively interacting with the screen while using the camera app offers the best preliminary test for digitizer failure.