Practice Test Geeks(CMT) Certified Mobile Tech Practice Test
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Device Hardware & Software Flashcards

7 cards from real CMT practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

Read the first 7 Device Hardware & Software flashcards as text

  1. Which Android diagnostic mode allows a technician to flash firmware, wipe partitions, and unlock the bootloader?

    Answer: Fastboot/Bootloader Mode

    Fastboot mode communicates with a host computer over USB to flash partitions, unlock the bootloader, and perform low-level device operations.

  2. A device's microphone works during calls but not during video recording. What is the most likely hardware cause?

    Answer: Secondary (noise-cancellation) microphone failure

    Many smartphones use a secondary microphone for video recording and noise cancellation; if it fails, calls (primary mic) still work but video audio does not.

  3. What technology allows a single physical SIM slot to support multiple carrier profiles without swapping physical cards?

    Answer: eSIM (Embedded SIM)

    eSIM is a programmable chip soldered to the motherboard that can store and switch between multiple carrier profiles without a physical SIM card.

  4. When reflashing stock firmware on an Android device, which file format is commonly used for Qualcomm-based devices?

    Answer: .mbn / .img via EDL (Qualcomm Emergency Download Mode)

    Qualcomm devices use EDL (Emergency Download Mode) with QFIL/QPST tools and .mbn or .img firmware files for deep-level flashing.

  5. A technician replaces a smartphone camera module, but the rear camera app shows a black screen. What should be checked first?

    Answer: Camera ribbon cable connection to the motherboard

    A loose or improperly seated camera flex cable is the most common cause of a black screen after a camera module replacement.

  6. What is the purpose of the 'haptic engine' (Taptic Engine on iPhone) in mobile devices?

    Answer: Creates precise tactile vibration feedback for touch interactions

    The haptic engine uses a linear actuator to produce precise, controlled vibrations that simulate physical button clicks and provide tactile UI feedback.

  7. A phone's screen flickers only when the battery is below 20%. Which scenario best explains this?

    Answer: Insufficient voltage at low battery causes display driver instability

    As battery voltage drops under load, the display driver IC may receive insufficient power, causing visible flickering before auto-shutdown triggers.