CMT Cheat Sheet 2026

The 30 highest-yield CMT facts, distilled from real exam questions. Print it, save it as a PDF, or study it here — free, no sign-up.

1. What does the USB Power Delivery (USB-PD) standard define? → A protocol allowing negotiated fast charging at higher voltages and currents over USB-C
2. Which component in a mobile device is responsible for wireless communication? → Wireless communication module
3. What is the purpose of mobile device encryption? → To track mobile device usage
4. What is the purpose of the 'haptic engine' (Taptic Engine on iPhone) in mobile devices? → Creates precise tactile vibration feedback for touch interactions
5. What is mobile device management (MDM)? → A set of tools to manage and secure mobile devices
6. What does a 'hard reset' of a mobile device do? → Fixes software bugs
7. Which Android diagnostic mode allows a technician to flash firmware, wipe partitions, and unlock the bootloader? → Fastboot/Bootloader Mode
8. A technician replaces a cracked display on a smartphone, but touch response is erratic afterward. What is the most likely cause? → Digitizer connector not fully seated
9. What does professional liability insurance (errors and omissions) protect a repair technician from? → Claims that the technician's work caused damage or loss to a customer's device or data
10. Which Wi-Fi frequency band offers the longest range but lowest throughput? → 2.4 GHz
11. Which app permission model approach is considered MOST secure for a mobile device? → Prompt the user for each permission at the time it is needed (runtime permissions)
12. A technician notices a mobile device battery is visibly bulging. What is the correct course of action? → Replace the battery immediately as it poses a fire and explosion risk
13. A customer asks for a repair that you believe is not cost-effective compared to a replacement. You should: → Honestly present both options with costs so the customer can decide
14. A phone charges slowly on all cables and chargers. A cotton swab reveals compacted lint in the charging port. What is the correct cleaning technique? → Carefully remove debris with a non-conductive plastic spudger or wooden toothpick
15. Which practice best demonstrates active listening when a customer describes a problem? → Paraphrasing the customer's description back to confirm understanding
16. A technician notices a mobile device is running an app with unusually high background data usage. What is the MOST likely security concern? → The app may be exfiltrating data to a remote server
17. Which component is responsible for measuring a device's orientation and rotation for screen auto-rotate? → Gyroscope
18. What does ESD (Electrostatic Discharge) protection during mobile repair primarily prevent? → Invisible damage to sensitive ICs from static electricity
19. Which practice is considered unethical in mobile device repair? → Billing for parts that were not used or replacing parts that did not need replacement
20. What is the role of Wi-Fi in mobile device connectivity? → To enable high-speed internet access through local networks
21. What is the purpose of Safe Mode on Android? → It boots the device with only pre-installed apps to isolate third-party app issues
22. What is 'shoulder surfing' in the context of mobile device security? → Physically observing a user's screen or keypad to steal PINs or passwords
23. What is Bluetooth technology used for in mobile devices? → To wirelessly connect to peripherals
24. A phone shows ghost touches (screen inputs with no physical contact) after a screen replacement. What is the most likely cause? → Poor quality or incompatible digitizer, or digitizer flex cable not fully seated
25. What is the purpose of a mobile hotspot? → To share cellular data with other devices
26. Why is it important to obtain customer authorization before performing additional repairs discovered during service? → To ensure the customer agrees to additional costs and maintains trust
27. Which of the following is a common mobile device processor brand? → Qualcomm Snapdragon
28. What is the primary security benefit of using eSIM technology over a physical SIM card? → eSIMs cannot be physically removed or swapped, reducing SIM-swap attack risk
29. A device intermittently loses Wi-Fi but cellular data works fine. The issue persists after OS reinstall. What is the most likely hardware cause? → Damaged Wi-Fi antenna or loose Wi-Fi module connector
30. What is the first step in troubleshooting a mobile device? → Identify the problem by assessing symptoms