220-1102 Question 344
Single answerVoice callA technician is troubleshooting an employee's smartphone that can browse websites and send instant messages over the cellular network, but every time the user tries to place a normal phone call, the call fails immediately. The issue occurs in multiple locations, and restarting the phone did not help. Which of the following is the MOST likely cause?
- A
Airplane mode is enabled on the phone
- B
The SIM card or mobile plan does not have voice service properly provisioned
- C
The phone's Wi-Fi connection is unstable
- D
The user has too many apps open in the background
Show answer and explanation
Correct answer: B
Explanation
The best answer is that the SIM card or mobile plan does not have voice service properly provisioned. In smartphone troubleshooting, technicians should distinguish between services that use mobile data and services that rely on carrier voice service. If a phone has working cellular data but cannot complete standard phone calls, the issue often points to carrier provisioning, SIM activation, account restrictions, or a missing voice feature on the line. As a best practice, verify account status with the carrier, confirm the device and SIM are activated correctly, and check whether the line includes voice service. This aligns with common mobile device troubleshooting processes emphasized in CompTIA A+ Core 2 objectives, where technicians must identify whether a problem is due to device settings, wireless connectivity, or carrier service configuration.
- A. Incorrect.
Incorrect. If airplane mode were enabled, the phone's cellular radios would be disabled, which would typically prevent both mobile data and standard cellular voice service from working. Because the user can browse websites and send messages over the cellular network, airplane mode is not the most likely cause.
- B. Correct.
Correct. If cellular data works but standard voice calls fail consistently, a likely cause is that the SIM card, carrier account, or line provisioning is not correctly set up for voice service. In real-world support, technicians verify whether the line is provisioned for voice, whether the SIM is activated correctly, and whether the carrier account has any restrictions or misconfigurations affecting calling.
- C. Incorrect.
Incorrect. An unstable Wi-Fi connection would not usually prevent a normal cellular voice call from going through, especially since the scenario states the phone can use the cellular network and the failure happens across multiple locations. This option might confuse Wi-Fi calling with standard carrier voice calls.
- D. Incorrect.
Incorrect. Too many background apps may affect performance or battery life, but they do not normally cause standard voice calls to fail immediately across multiple locations. This is a plausible distractor because users often blame app load for phone issues, but it does not fit the symptoms as well as a provisioning problem.