CompTIA A+ Core 1 (220-1201)Hardware and Network TroubleshootingMedium
A user complains that their smartphone's touchscreen registers taps in the wrong location, is unresponsive in certain areas, and sometimes activates apps without being touched. The technician has already restarted the phone and updated the OS with no improvement. Which of the following is the MOST likely cause?
- AFaulty digitizer
- BCorrupted display driver
- CDepleted battery
- DMalware infection
Show answer & explanationAnswer & explanation
Correct answer: A. Faulty digitizer
Ghost touches, misregistered taps, and dead zones on a touchscreen after a reboot and OS update point to a hardware fault in the digitizer, the layer responsible for detecting touch input.
Why the other options are wrong
- B. Mobile OSes don't use separate display drivers the way desktops do, and this wouldn't explain touch inaccuracy.
- C. A dying battery causes shutdowns or performance issues, not touch inaccuracies.
- D. Malware could cause erratic behavior but wouldn't typically cause localized dead zones.
Digitizer Failure
The digitizer is the touch-sensing layer on a mobile device screen; when it fails, symptoms include ghost touches, unresponsive zones, and inaccurate tap registration.
- Digitizer is separate from the LCD/OLED display panel
- Common causes: physical damage, moisture, aging adhesive
- Symptoms: ghost touches, dead zones, misregistration
Memory trick: 'Ghost Touches = Ghost in the Digitizer.'