A technician is troubleshooting several mobile device issues brought to the help desk. Match each reported hardware or display symptom on the left with its most likely root cause or component failure on the right.
- A laptop screen remains completely dark during operation, but a dim image of the desktop is visible when shining a flashlight directly onto the glass panel.Failed high-voltage display inverter or backlight power supply.
- A smartphone screen is lifting away from its frame, and the touchpad/glass assembly is bulging outward.Swollen lithium-ion battery requiring immediate hazardous material handling and replacement.
- A tablet registers touch inputs several inches away from where the user actually taps the screen after a low-height drop.Unseated or damaged digitizer ribbon cable connection.
- A laptop experiences weak and intermittently dropping Wi-Fi signals immediately following a display panel replacement.Pinched or disconnected internal wireless antenna cables routed inside the display bezel.
Answer
Match the symptoms to components as follows: 1) Very dim screen visible with flashlight maps to failed display inverter or backlight power supply; 2) Bulging screen/chassis maps to swollen lithium-ion battery; 3) Misaligned touch registration maps to unseated or damaged digitizer ribbon cable; 4) Weak Wi-Fi after display disassembly maps to pinched or disconnected internal wireless antenna cables.
Each symptom directly corresponds to a specific hardware component failure: faint image under external light indicates backlight/inverter failure; chassis bulging indicates a hazardous swollen battery; inaccurate touch coordinates indicate digitizer cable issues; and poor wireless reception following screen repair indicates damaged or disconnected Wi-Fi antenna leads routed inside the bezel.
Step-by-Step Solution
Key Concept
Mobile Device Hardware & Display Failure Isolation