220-1101 Mobile Devices Practice Question

A user's smartphone will not charge when plugged into a cable. The technician inspects the charging port and finds it is clean and the cable appears undamaged. The phone was working normally earlier and was not dropped. The technician tests the cable with another device and it charges normally. Which of the following should the technician do NEXT to diagnose the issue?

⚠ Common exam trap

Test-takers frequently assume a clean port and undamaged cable mean the phone's battery must be dead, leading them to replace the battery prematurely, rather than systematically testing with a known-good charger and cable first.

Answer choices

Why each option matters

Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.

Correct answer & explanation

✓

Test the phone with a different, known-good charger and cable

Since the cable works with another device and the charging port is clean, the issue is isolated to the phone's charging circuit or battery management system. Testing with a known-good charger and cable eliminates variables and confirms whether the phone itself is rejecting power, which is the standard next step in CompTIA A+ troubleshooting methodology.

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

✗
Replace the battery with a new one
Why it's wrong here
Replacing the battery is a physical repair step, not a diagnostic one — it doesn't verify what's actually causing the failure to charge and can't be cheaply undone. Testing with a known-good charger and cable is a reversible, zero-cost step that isolates whether the fault lies in the accessories or the phone itself, following standard test-before-repair troubleshooting order.
✓
Test the phone with a different, known-good charger and cable
Why this is correct
Testing with a different, known-good charger and cable is the correct first diagnostic step because it splits the charging system into two halves: the external accessories versus the internal hardware. If the phone charges normally with the known-good pair, the original charger or cable is faulty; if it still fails, the problem lies inside the phone (charging port, battery, or charging IC). This is a zero-cost, reversible test that follows standard test-before-repair methodology, and it avoids unnecessary part replacement.
✗
Perform a factory reset of the smartphone
Why it's wrong here
Performing a factory reset is incorrect because it only clears software configuration, user data, and installed applications — it has no effect on the physical charging path or power management hardware. The phone's inability to charge is a hardware-level failure; unless there were symptoms of a software crash or corrupted firmware (e.g., boot loops, app errors, sudden shutdowns), a reset cannot repair a dead charging port, faulty battery, or damaged cable. Moreover, a factory reset is destructive and irreversible, so it should never be used as a diagnostic step before ruling out external and internal hardware issues.
✗
Replace the charging port assembly
Why it's wrong here
Replacing the charging port assembly is premature and invasive because it assumes the port is defective without isolating the fault. A damaged charger, frayed cable, or even a battery that has entered a protective fail-safe state can produce the exact same symptom — no charging — while the port itself remains fully functional. Proper troubleshooting requires using a known-good charger and cable, inspecting the port for debris or bent pins, and possibly measuring voltage with a multimeter before any soldering or part replacement. Replacing the port without confirming the root cause risks spending money and introducing a new failure point for no benefit.

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220-1101 Mobile Devices Practice Question

Why each option matters

Option-by-option breakdown

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