220-1101 Mobile Devices — Timed 100 Questions

Question 1

A user reports that the touchscreen on their smartphone is unresponsive in the bottom-left corner but works everywhere else. Which component is most likely failing?

Accepted Answer

Digitizer failure. The touchscreen's digitizer is the layer responsible for detecting touch input. When a specific region of the screen becomes unresponsive while the display itself remains functional, it indicates a localized failure of the digitizer's grid or controller, not the LCD panel.

Answer

Dead pixels

Answer

LCD backlight issue

Answer

Pending OS update

Question 2

A user reports that their smartphone battery drains significantly faster after a recent OS update. Which of the following should the technician do FIRST to address this issue?

Accepted Answer

Check the battery usage statistics in the settings menu. Option C is correct because the first step in troubleshooting battery drain after an OS update is to check the battery usage statistics in the settings menu. This allows the technician to identify which apps or services are consuming excessive power, often due to background processes or misconfigured settings introduced by the update. Replacing hardware or performing a full OS reinstall without first diagnosing the cause is premature and may not resolve the issue.

Answer

Replace the battery with a new one

Answer

Perform a factory reset and restore from backup

Answer

Reinstall the operating system using the latest firmware

Question 3

A user's smartphone running Android is unable to connect to any Wi-Fi network. The Wi-Fi toggle is grayed out and cannot be turned on. The technician has tried a soft reset and checked that Airplane Mode is off. Which of the following is the most likely cause?

Accepted Answer

Faulty Wi-Fi antenna or module. When the Wi-Fi toggle is grayed out and cannot be enabled, even after a soft reset and confirming Airplane Mode is off, it typically indicates a hardware-level failure. The most common cause is a faulty Wi-Fi antenna or module, as the operating system detects the hardware is not responding and disables the toggle to prevent user attempts. Software issues like corrupted settings or incorrect date/time would not prevent the toggle from being physically movable.

Answer

Corrupted network configuration

Answer

Incorrect date and time

Answer

Disabled Wi-Fi adapter in BIOS

Question 4

A user's iPhone will not charge even though the screen is cracked but still displays properly and responds to touch. The technician has cleaned the Lightning port and verified the charging cable and power adapter work with another device. Which component most likely needs replacement?

Accepted Answer

Replace the charging port flex cable. The iPhone charges through the Lightning port, which is connected to the logic board via the charging port flex cable. Since the screen is cracked but still displays and responds to touch, the LCD and digitizer are functional. The technician has already ruled out the cable and power adapter, so the most likely failure is the charging port flex cable, which can be damaged by debris, corrosion, or physical stress from the cracked screen.

Answer

Replace the LCD assembly

Answer

Replace the digitizer

Answer

Replace the battery

Question 5

A user reports that their laptop's touchpad is not working. The technician checks Device Manager and sees the touchpad is not listed. The function key (Fn + F7) that enables/disables the touchpad does not seem to respond. The technician has rebooted the laptop. Which of the following should the technician try NEXT?

Accepted Answer

Check BIOS settings for touchpad enable/disable. The touchpad not appearing in Device Manager and the Fn key not responding suggests the device is disabled at a lower level than the OS, such as in the BIOS/UEFI firmware. Checking BIOS settings is the correct next step because many laptops have a hardware-level enable/disable toggle for the touchpad that overrides OS and driver settings. This is a standard troubleshooting step before attempting driver updates or hardware replacement.

Answer

Update the touchpad driver via Windows Update

Answer

Replace the touchpad hardware

Answer

Run the System File Checker (sfc /scannow)

Question 6

A user's Android smartphone screen is flickering intermittently and occasionally goes black for a few seconds before returning. The phone has not been dropped or exposed to moisture. The technician has performed a factory reset, but the issue persists. Which component is the MOST likely cause of the problem?

Accepted Answer

Display assembly. The display assembly includes both the LCD panel and the digitizer. Since the issue persists after a factory reset, it is hardware-related. Intermittent flickering and blackouts without physical damage or moisture point to a failing LCD panel or loose internal connection within the display assembly, not the digitizer (which handles touch input only).

Answer

Digitizer

Answer

Battery

Answer

Motherboard

Question 7

A user's smartphone will not charge when plugged into a wall charger. The technician tests the charger with another phone and it works correctly. The technician then inspects the charging port on the smartphone and notices debris inside. Which of the following is the BEST first step to resolve the issue?

Accepted Answer

Clean the charging port with a toothpick. Option C is correct because the technician has already verified that the charger works with another phone, isolating the issue to the smartphone itself. Inspecting the charging port revealed debris, which is a common cause of poor electrical contact. Cleaning the port with a non-conductive, non-metallic tool like a toothpick is the safest and most effective first step to restore connectivity without damaging the port's pins or internal components.

Answer

Replace the smartphone battery

Answer

Replace the charging port assembly

Answer

Perform a factory reset on the smartphone

Question 8

A user's Android smartphone is experiencing intermittent touchscreen unresponsiveness, especially in the bottom corners. The screen has no visible cracks or damage. Which of the following troubleshooting steps should the technician perform FIRST?

Accepted Answer

Remove the screen protector and clean the screen. Intermittent touchscreen unresponsiveness, especially in the bottom corners, is often caused by a screen protector that is lifting, trapping debris, or creating air gaps that interfere with the capacitive touch layer. The first step should be to remove the screen protector and clean the screen with a microfiber cloth, as this is the least invasive and most likely fix for the described symptoms.

Answer

Perform a factory reset

Answer

Replace the touchscreen digitizer

Answer

Update the device firmware

Question 9

A user reports that their mobile phone's battery drains significantly faster than normal. The technician checks the battery usage statistics and finds that a specific social media app is consuming an unusually high percentage of battery. Which of the following is the FIRST step the technician should take to resolve the issue?

Accepted Answer

Force stop the application. Force stopping the application immediately halts the misbehaving process and its background services, which is the fastest way to stop excessive battery drain without affecting other system components. This is the first troubleshooting step because it isolates the issue to the app itself, allowing the technician to verify if the app is the root cause before taking more drastic measures.

Answer

Replace the battery

Answer

Recalibrate the battery

Answer

Perform a factory reset

Question 10

After a user updates their iPhone to the latest iOS version, the device can no longer connect to the cellular network. The SIM card is recognized, Wi-Fi works, and the phone can make calls over Wi-Fi (VoWiFi). The technician performed a network settings reset and a full restore from a backup, but the issue persists. Which of the following is the MOST likely cause?

Accepted Answer

The iPhone's baseband hardware has failed. The correct answer is C because the symptoms—SIM recognized, Wi-Fi and VoWiFi working, but no cellular connectivity after an iOS update—point to a hardware-level baseband failure. The baseband processor handles cellular radio functions; an update cannot corrupt hardware, but it can expose a pre-existing latent hardware fault. Since a network settings reset and full restore from backup did not resolve the issue, the problem is not software or firmware, leaving physical baseband hardware failure as the most likely cause.

Answer

The SIM card is damaged or locked to a different carrier

Answer

The iOS baseband firmware is corrupted

Answer

The iOS update introduced a compatibility issue with the carrier

Question 11

A user reports that their Android smartphone no longer charges when connected to a wall charger. The technician tries a different charging cable and power adapter, but the phone still does not charge. The phone's charging port appears clean and free of debris. The technician then attempts to charge the phone using a wireless charging pad, and the phone charges successfully. Which of the following is the most likely cause of the issue?

Accepted Answer

The USB-C connector on the charging port is damaged.. The correct answer is B because the phone charges wirelessly but not via the USB-C port, which isolates the issue to the wired charging circuit. Since different cables and adapters were tried and the port is clean, the most likely cause is physical damage to the USB-C connector, such as bent pins or worn contacts, preventing proper electrical connection. Wireless charging uses a separate coil and circuit, so its functionality confirms the battery and power management system are intact.

Answer

The smartphone's battery has reached end of life.

Answer

The wireless charging coil is malfunctioning.

Answer

The operating system has a power management bug.

Question 12

A user reports that their iPhone's touchscreen is unresponsive after the device was accidentally dropped in a puddle. The technician dries the phone, performs a forced restart, and cleans the screen, but the touch remains unresponsive. However, the display still shows images correctly. Which component is most likely damaged?

Accepted Answer

Digitizer. The digitizer is the component responsible for converting touch input into electrical signals. Since the display still shows images correctly but the touchscreen is unresponsive, the LCD panel and backlight are functioning, isolating the damage to the digitizer layer.

Answer

LCD panel

Answer

Backlight

Answer

Battery

Question 13

A user's Android tablet was dropped and the glass digitizer cracked, but the LCD display still shows images correctly. The user reports that touch input is unresponsive in several areas of the screen. Which of the following replacement procedures is MOST appropriate?

Accepted Answer

Replace the entire screen assembly (LCD and digitizer together). When the glass digitizer is cracked but the LCD display still functions, the digitizer (touch panel) is the damaged component. However, in most modern Android tablets, the digitizer is fused to the LCD as a single screen assembly, making it impractical or impossible to replace only the digitizer without damaging the LCD. Therefore, replacing the entire screen assembly (LCD and digitizer together) is the most appropriate procedure to restore full touch functionality.

Answer

Replace only the LCD display

Answer

Replace only the digitizer (touch panel)

Answer

Perform a touchscreen recalibration

Question 14

A user's smartphone (Android) will not charge via the USB-C port. The technician tries a different cable and charger, and also tries cleaning the port with compressed air. The phone still does not charge. However, the phone can be recognized by a computer when connected via USB. Which of the following should the technician try next?

Accepted Answer

Inspect the port for bent pins.. The correct answer is C because the phone can still communicate data over USB (recognized by a computer), which proves the power and data lines are partially functional, but a bent pin in the USB-C connector can break the power delivery (PD) negotiation or the VBUS connection required for charging. Cleaning with compressed air only removes debris, not physical damage like bent pins, so a visual inspection is the logical next step.

Answer

Replace the battery.

Answer

Perform a factory reset.

Answer

Update the phone's firmware.

Question 15

A user reports that their Android smartphone displays 'Emergency calls only' at the top of the screen and cannot make or receive regular calls. The device still connects to Wi-Fi and can use messaging apps over Wi-Fi. The technician removes the SIM card, inspects it for damage, and reinserts it. The problem persists. The technician then takes a known-working SIM card from another phone and inserts it into the user's phone; the phone immediately connects to the cellular network. Which of the following is the MOST likely cause?

Accepted Answer

The SIM card is defective or has been deactivated by the carrier.. The technician's swap test with a known-working SIM card immediately restored cellular connectivity, isolating the issue to the original SIM card. Since the phone could still use Wi-Fi and messaging apps, the radio hardware and software stack for cellular were functional, but the SIM card itself was either physically defective or deactivated by the carrier, preventing network registration.

Answer

The phone's cellular antenna is disconnected or damaged.

Answer

The phone is in airplane mode but Wi-Fi is manually re-enabled.

Answer

The mobile network APN settings are incorrectly configured.

Question 16

A user reports that their Android smartphone's battery drains significantly faster than usual. The technician checks the battery usage statistics and finds that the screen is consuming 60% of the battery. The screen brightness is manually set to maximum. Which of the following is the MOST effective step to reduce battery consumption?

Accepted Answer

Reduce screen brightness. The screen is the primary battery consumer, and manual maximum brightness forces the display to use full backlight power. Reducing screen brightness directly lowers the power draw of the display, which is the most effective immediate step to extend battery life. This addresses the root cause identified in the battery usage statistics.

Answer

Disable mobile data

Answer

Remove the battery and reinsert it

Answer

Perform a factory reset

Question 17

A user reports that their Android smartphone will not charge when placed on a wireless charging pad. The phone charges normally when connected via a USB cable. The technician tests the wireless charging pad with another smartphone, and it works fine. Which of the following is the MOST likely cause of the issue?

Accepted Answer

The phone case is interfering with the wireless charging. Option C is correct because a thick, metallic, or improperly designed phone case can block or interfere with the electromagnetic field used for inductive charging. Since the charging pad works with another phone and the phone charges via USB, the issue is specific to the phone's ability to receive the wireless signal, and the case is the most common physical barrier.

Answer

The wireless charging coil inside the phone has failed

Answer

The phone is not placed correctly on the charging pad

Answer

A software setting is disabling wireless charging

Question 18

A user's iPhone 11 is stuck in a boot loop after an attempted jailbreak. The device repeatedly shows the Apple logo and then restarts. The technician connects the iPhone to a computer; iTunes displays a message that the device is in recovery mode and must be restored. The technician attempts a force restart and tries a different USB cable and computer, but the iPhone remains in recovery mode and enters the boot loop after any restore attempt. Which of the following is the NEXT best step?

Accepted Answer

Perform a DFU restore. The iPhone is stuck in a boot loop after a failed jailbreak, and standard recovery mode restores are failing. A DFU (Device Firmware Update) restore bypasses the bootloader and iBoot, allowing the device to be completely wiped and the firmware reinstalled at the lowest level, which is necessary to recover from a corrupted boot chain caused by the jailbreak attempt.

Answer

Replace the battery

Answer

Replace the logic board

Answer

Update iOS using over-the-air (OTA)

Question 19

A user reports that their iPhone's battery drains quickly throughout the day. The technician checks the Battery settings and sees that the display is the top consumer at 40%. The user mentions the screen is very bright outdoors. Which of the following settings would MOST effectively reduce battery drain in this scenario?

Accepted Answer

Enable Auto-Brightness.. Enabling Auto-Brightness allows the phone to adjust screen brightness based on ambient light, reducing power consumption when full brightness is not needed. This directly addresses the high display battery usage.

Answer

Turn off Bluetooth.

Answer

Disable Background App Refresh.

Answer

Reduce the screen resolution.

Question 20

A user reports that during phone calls on their Android smartphone, the caller's voice sounds very low and muffled through the earpiece speaker. The technician has cleaned the speaker grille with a soft brush and the issue persists. The phone otherwise functions normally with media sounds playing at adequate volume. Which of the following should the technician check NEXT?

Accepted Answer

Check the call volume setting and adjust it during a test call. The correct answer is A because the symptom—low and muffled voice specifically during calls, with normal media volume—points to a call volume setting being too low, not a hardware failure. The technician should first adjust the in-call volume during a test call, as this is a separate software-controlled gain stage from media volume. Since cleaning the grille didn't resolve it, the next logical step is to verify and adjust the call volume slider, which is a common user-misconfiguration issue.

Answer

Replace the earpiece speaker module

Answer

Disable Bluetooth to rule out audio redirection

Answer

Reset the audio codec settings in developer options