220-1102 Question 317
Single answerMotion sensorsA user reports that their smartphone frequently turns on and displays a black screen with a lock icon while it is in a pocket or bag, causing unnecessary battery drain. The touchscreen itself is functioning normally. As the technician, which action is the BEST way to reduce these accidental wake events while preserving normal phone use?
- A
Disable the phone's motion/raise-to-wake feature in settings
- B
Recalibrate the touchscreen digitizer
- C
Replace the ambient light sensor
- D
Enable airplane mode whenever the phone is not in use
Show answer and explanation
Correct answer: A
Explanation
The best answer is to disable the motion or raise-to-wake feature. In real-world mobile device troubleshooting, technicians should first identify which sensor or setting is tied to the reported symptom. Motion sensors, typically the accelerometer and sometimes the gyroscope, are commonly used by mobile operating systems to detect movement and trigger screen wake functions. If a device wakes while in a pocket or bag, the most appropriate corrective action is to adjust the motion-related setting rather than replacing unrelated hardware. This follows standard troubleshooting best practices: confirm the symptom, identify the relevant feature, and apply the least invasive fix first. Smartphone vendors commonly document features such as raise-to-wake or lift-to-wake in device settings and support articles, and CompTIA A+ Core 2 expects candidates to recognize how mobile device sensors affect usability, security, and battery life.
- A. Correct.
Correct. Many smartphones use motion-related sensors such as an accelerometer and gyroscope to support features like raise-to-wake, lift-to-check, or motion wake. If the phone is waking in a pocket or bag, disabling that motion-triggered wake feature is the most direct and least disruptive fix. This addresses the actual symptom without affecting core functionality such as calls, apps, or the touchscreen.
- B. Incorrect.
Incorrect. A digitizer issue would affect touch input accuracy, ghost touches, or dead spots on the screen. In this scenario, the screen is waking unexpectedly, but touch functionality is normal. Recalibrating or replacing the digitizer would not address motion-triggered wake behavior.
- C. Incorrect.
Incorrect. The ambient light sensor adjusts brightness and may assist with auto-brightness or screen behavior in some devices, but it is not the primary component responsible for motion-based wake events. Replacing it would not be the best first step for a phone waking when moved in a pocket or bag.
- D. Incorrect.
Incorrect. Airplane mode disables wireless radios, which may reduce some battery usage, but it does not directly stop motion sensors from waking the display. It is also impractical because it prevents calls, texts, and data connectivity, making it a poor solution for normal day-to-day use.