What indicates that the digitizer is damaged during testing?

The indication that the digitizer is damaged is reflected in the scenario where the focus fails to follow touch or moves on its own. This behavior suggests a dysfunction in the digitizer—a component responsible for translating touch inputs into actions on the screen. A damaged digitizer may misinterpret inputs or fail to register them entirely, leading to erratic movements or a lack of responsiveness when interacting with the device. This prompts further investigation, as it directly affects the user experience and the device's functionality.

In contrast, while other options may suggest issues within the device, they do not specifically point to digitizer damage. For instance, if the screen lights up but doesn't display images, it may indicate a problem with the display itself rather than the digitizer. Similarly, rapid battery drainage often stems from software issues or battery health concerns, and poor Wi-Fi connectivity can arise from network settings or hardware issues unrelated to the digitizer. Thus, the behavior of the focus failing to track touch signals a clear problem with the digitizer's operation.