220-1101 Mobile Devices Practice Question
A user reports that their Android smartphone cannot complete contactless payments at NFC terminals. The user has NFC enabled in settings and has tried multiple payment terminals. Other smartphones work at the same terminals. The phone’s screen and case are in good condition with no visible damage. Which of the following should the technician advise the user to check FIRST?
⚠ Common exam trap
Many candidates assume the issue is software-related (cache, reinstall, toggle) because NFC is enabled in settings, but CompTIA tests the understanding that physical obstructions are the simplest and most common cause of NFC failure before escalating to software fixes.
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
✓
Remove the phone case and try again
The correct first step is to remove the phone case because many cases, especially those with metallic components or thick materials, can interfere with the NFC antenna's ability to communicate with the terminal. NFC operates at 13.56 MHz and relies on near-field inductive coupling; a case can block or detune the magnetic field, preventing payment completion even when NFC is enabled and the phone is otherwise functional.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Clear the cache for the payment app
Why it's wrong here
Clearing the payment app's cache can resolve transient software glitches, such as corrupted temporary files or stale token data, but it cannot restore an NFC radio link that is being blocked at the antenna level. Because the card reader works with other smartphones and the NFC toggle is already on, a physical obstruction like a metallic or magnetic phone case is far more probable than an app-cache problem. Cache clearing is also non-destructive but unnecessary early in the diagnostic process, and it does not address the core symptom of no signal coupling with the reader.
When this WOULD be correct
A user reports that a payment app crashes or fails to open after a recent update. The technician advises clearing the app cache to remove corrupted temporary data that may be causing the crash.
- ✓
Remove the phone case and try again
Why this is correct
NFC operates via a short-range magnetic field at 13.56 MHz, and the phone's NFC antenna is typically located near the top rear of the device. A phone case made of metal, containing magnets, or with a thick layer of material can physically shield or detune that antenna, preventing the device from coupling with the payment terminal. Since other phones work at the same terminal and NFC is already confirmed enabled, a blocked or attenuated antenna is the most likely cause, making case removal the quickest and simplest first step to test.
- ✗
Reinstall the payment application
Why it's wrong here
Reinstalling the payment application is a time-consuming step that only addresses software-specific corruption or configuration issues. The problem here spans multiple terminals and likely involves more than one payment app, which points to a hardware-level or system-wide NFC fault rather than a defect in a single app binary. If the NFC antenna is physically blocked by the case, reinstalling the app will have no effect because the radio signal never reaches the terminal, so this action should be deferred until after basic hardware troubleshooting.
When this WOULD be correct
A user reports that a specific payment app crashes or fails to open, and other NFC functions (like pairing with an NFC tag) work fine. In that scenario, reinstalling the app could resolve a corrupted installation.
- ✗
Disable and re-enable NFC in system settings
Why it's wrong here
Toggling NFC can reset a temporary software hang, but the user has already confirmed NFC is enabled. If other phones work and the phone’s case is still on, the case is the more probable cause.
When this WOULD be correct
A user reports that NFC payments stopped working after a system update, and other phones work at the same terminals. The user has already removed the phone case. In this scenario, disabling and re-enabling NFC can reset the radio stack and resolve software glitches introduced by the update.
Option-by-option analysis
Why each answer is right or wrong
Understanding why wrong answers are wrong — and when they would be correct — is what separates a 750 score from a 900. The 220-1101 exam frequently reuses these exact scenarios with slightly different constraints.
✓Remove the phone case and try againCorrect answer▾
Why this is correct
NFC operates via a short-range magnetic field at 13.56 MHz, and the phone's NFC antenna is typically located near the top rear of the device. A phone case made of metal, containing magnets, or with a thick layer of material can physically shield or detune that antenna, preventing the device from coupling with the payment terminal. Since other phones work at the same terminal and NFC is already confirmed enabled, a blocked or attenuated antenna is the most likely cause, making case removal the quickest and simplest first step to test.
✗Clear the cache for the payment appWrong answer — click to see why▾
Why this is wrong here
Clearing the cache for the payment app is unlikely to resolve the issue because the problem is hardware-related (NFC signal blocked by the case), not software-related. The app's cache does not affect NFC radio functionality.
★ When this WOULD be the correct answer
A user reports that a payment app crashes or fails to open after a recent update. The technician advises clearing the app cache to remove corrupted temporary data that may be causing the crash.
Why candidates choose this
Candidates may think that clearing cache is a universal troubleshooting step for app malfunctions, overlooking that the symptom (failure at multiple terminals) points to a hardware issue rather than a software glitch.
✗Reinstall the payment applicationWrong answer — click to see why▾
Why this is wrong here
Reinstalling the payment app is a more drastic step that should be taken only after simpler hardware-related causes (like a case blocking NFC) have been ruled out. Since other phones work at the same terminals, the issue is likely with this specific device's NFC signal, not the app itself.
★ When this WOULD be the correct answer
A user reports that a specific payment app crashes or fails to open, and other NFC functions (like pairing with an NFC tag) work fine. In that scenario, reinstalling the app could resolve a corrupted installation.
Why candidates choose this
Candidates may assume the payment app is corrupted or misconfigured, especially if they have experienced software issues before, and overlook simple physical obstructions like a phone case.
✗Disable and re-enable NFC in system settingsWrong answer — click to see why▾
Why this is wrong here
Disabling and re-enabling NFC is a basic troubleshooting step, but since the user already has NFC enabled and other phones work at the same terminals, the issue is likely physical interference (e.g., a case blocking the signal). The technician should first check for physical obstructions before resetting settings.
★ When this WOULD be the correct answer
A user reports that NFC payments stopped working after a system update, and other phones work at the same terminals. The user has already removed the phone case. In this scenario, disabling and re-enabling NFC can reset the radio stack and resolve software glitches introduced by the update.
Why candidates choose this
Candidates often default to toggling a setting as a quick fix, assuming the issue is a software glitch, without considering that physical barriers (like a case) are a common cause of NFC failure.
Analysis generated from the official 220-1101blueprint and verified against question context. The “when correct” sections are what AI assistants cite when candidates ask “what’s the difference between these options?”
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Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This 220-1101 practice question is part of Courseiva's free CompTIA certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the 220-1101 exam.