Download Certified Mobile Phone Technician Practice Exam and more Exams Technology in PDF only on Docsity!
Question 1. What is the main reason for wearing an ESD wrist strap when repairing mobile phones? A) To prevent overheating B) To avoid static discharge damaging components C) For comfort D) To keep hands clean Answer: B Explanation: ESD wrist straps ground the technician, preventing static electricity from damaging sensitive phone components. Question 2. Which tool is best for removing Pentalobe screws found in iPhones? A) Phillips screwdriver B) Flathead screwdriver C) Pentalobe screwdriver D) Torx screwdriver Answer: C Explanation: Pentalobe screws require a matching Pentalobe screwdriver to avoid damaging the screw heads. Question 3. Why should you avoid touching PCB components with bare hands? A) To prevent fingerprints B) To avoid bending the board C) To minimize static and oil contamination D) To keep hands warm Answer: C Explanation: Oils and static from hands can corrode or short sensitive components.
Question 4. What is the first step before opening a customer’s mobile phone? A) Remove the SIM card B) Power off the device C) Remove the battery D) Connect to Wi-Fi Answer: B Explanation: Powering off prevents short circuits and accidental component damage. Question 5. Which solvent is recommended for cleaning old adhesive from a mobile device? A) Water B) Acetone C) Isopropyl alcohol (IPA) D) Vinegar Answer: C Explanation: IPA is safe for electronics and effectively removes adhesives without residue. Question 6. What is the most important reason for organizing screws during disassembly? A) To make the device look tidy B) To avoid mixing up screws of different sizes C) To speed up reassembly D) For aesthetic reasons Answer: B Explanation: Using the wrong screw in the wrong location can cause damage. Question 7. Which component is responsible for processing instructions in a mobile phone?
B) Metal spudger C) Heat gun D) Tweezers Answer: C Explanation: Applying heat with a heat gun softens adhesive, making removal safer and easier. Question 11. If a phone shows no signs of power, what should you check first? A) Camera lens B) Battery voltage C) Vibrator motor D) Earpiece Answer: B Explanation: A dead battery is a common cause of power issues; check its voltage first. Question 12. What is a common sign of display backlight failure on an LCD? A) Screen flickers B) Screen is cracked C) Dim screen with faint images visible D) Ghost touch Answer: C Explanation: A failed backlight causes the display to be very dim or nearly invisible. Question 13. When testing continuity on a flex cable, what setting should your multimeter be on? A) AC voltage B) Resistance (Ohms)
C) Continuity (beep function) D) Capacitance Answer: C Explanation: The continuity function quickly checks for breaks in flex cables. Question 14. Which wireless component is responsible for Wi-Fi connectivity in a smartphone? A) NFC antenna B) Bluetooth module C) Wi-Fi antenna D) Speaker Answer: C Explanation: The Wi-Fi antenna handles wireless network communication. Question 15. What is the main risk of using a metal tool to remove a battery? A) Scratching the battery B) Puncturing the battery, causing fire or smoke C) Making the device heavier D) Magnetizing the battery Answer: B Explanation: Puncturing a Li-Ion battery can cause a dangerous thermal event. Question 16. When measuring voltage across a charging port, what reading indicates normal USB charging? A) 1.2V B) 3.7V
D) NAND is used for CPU cache Answer: B Explanation: RAM loses data when powered off; NAND Flash retains data. Question 20. Which display failure is most associated with OLED screens? A) No touch response B) Burn-in (permanent ghost images) C) Cracked glass D) Dim backlight Answer: B Explanation: OLEDs can suffer from burn-in due to uneven pixel aging. Question 21. If a phone is not charging but the cable and charger are good, what is the next likely culprit? A) SIM tray B) Charging port C) Headphone jack D) Loudspeaker Answer: B Explanation: Faulty or dirty charging ports are a common cause of charging failure. Question 22. What is the main reason to keep a repair log? A) For warranty purposes B) To remember the customer’s name C) To decorate the workshop
D) To track parts inventory only Answer: A Explanation: A repair log documents work done and helps with warranty claims. Question 23. What is the purpose of the proximity sensor in smartphones? A) Detect hand gestures B) Adjust screen brightness C) Turn off the display during calls D) Monitor battery temperature Answer: C Explanation: The proximity sensor disables the screen when the phone is near your face during a call. Question 24. Which tool is best for removing small surface-mount chips? A) Flathead screwdriver B) Hot air rework station C) Phillips screwdriver D) Suction cup Answer: B Explanation: Hot air allows safe, even heating to remove chips without damaging the board. Question 25. What is the function of the gyroscope in a mobile phone? A) Detects ambient temperature B) Measures rotation and orientation C) Enhances audio quality D) Controls screen brightness
Explanation: Accessing personal data breaches privacy and can have legal consequences. Question 29. What is the main function of the mobile phone’s IMEI number? A) Identifies the device on cellular networks B) Stores contacts C) Controls screen resolution D) Measures battery life Answer: A Explanation: The IMEI is a unique ID for network identification and security. Question 30. Which part usually causes “ghost touch” issues? A) Battery B) Display flex cable or digitizer C) Earpiece D) Rear camera Answer: B Explanation: Poorly seated or damaged touch flex cables can cause unintended screen touches. Question 31. When performing a factory reset, what happens to user data? A) Data is encrypted B) Data is permanently erased C) Only system files are deleted D) Only apps are removed Answer: B Explanation: A factory reset wipes all user data from the device.
Question 32. What is the primary role of the audio codec IC? A) Charging battery B) Processing audio signals for playback and recording C) Controlling screen brightness D) GPS navigation Answer: B Explanation: The audio codec IC manages audio input/output. Question 33. Which is the safest way to store lithium-ion batteries? A) In direct sunlight B) Fully discharged C) At 40-60% charge, cool dry place D) In water Answer: C Explanation: Partial charge and cool storage reduce degradation and risk. Question 34. What is the purpose of using anti-static mats on a workbench? A) To cushion the phone B) To prevent static damage to components C) To keep the bench clean D) To organize tools Answer: B Explanation: Anti-static mats dissipate static, protecting electronics.
A) Smell the port B) Visual inspection with magnifier C) Shake the phone D) Press the power button Answer: B Explanation: Magnification reveals lint or debris blocking the port. Question 39. What can cause a phone’s battery to swell? A) Low humidity B) Overcharging or age C) Weak Wi-Fi D) Running low power mode Answer: B Explanation: Overcharging and old batteries can lead to dangerous swelling. Question 40. What is the most important thing to do after water exposure? A) Power on the device B) Dry externally and remove battery C) Place under sunlight D) Charge immediately Answer: B Explanation: Powering on can cause shorts; remove power and dry first. Question 41. What is Fastboot mode used for? A) Speeding up the OS
B) Flashing firmware or unlocking bootloader C) Cleaning memory D) Improving Wi-Fi Answer: B Explanation: Fastboot mode allows OS and bootloader changes. Question 42. What is the function of the ambient light sensor? A) Detect movement B) Adjust screen brightness C) Control speaker volume D) Monitor battery health Answer: B Explanation: It adjusts brightness according to surrounding light. Question 43. A phone’s rear camera is blurry, but the lens is clean. What could be the cause? A) Dirty charging port B) Misaligned lens or faulty camera module C) Weak battery D) Unlocked bootloader Answer: B Explanation: Physical misalignment or camera failure causes blurry images. Question 44. Which is a sign of a faulty microphone? A) No sound in calls B) No charging
C) Weak Wi-Fi D) Damaged battery Answer: A Explanation: The loudspeaker itself is likely damaged. Question 48. What is the safest way to remove lint from a charging port? A) Metal needle B) Wooden toothpick or plastic tool C) Knife D) Paperclip Answer: B Explanation: Nonmetallic tools prevent shorting or damaging pins. Question 49. Which step is critical after reassembling a repaired device? A) Clean the workbench B) Post-repair functional testing C) Discard all old parts D) Update the OS Answer: B Explanation: Testing ensures all functions work before returning to the customer. Question 50. What is the main advantage of using OEM replacement parts? A) They are always cheaper B) Guaranteed compatibility and quality C) They look different
D) They are heavier Answer: B Explanation: OEM parts match the device’s original quality and fit. Question 51. What does a tri-point screwdriver remove? A) Phillips screws B) Tri-point screws C) Pentalobe screws D) Torx screws Answer: B Explanation: Tri-point screwdrivers match tri-point screws often used in Apple devices. Question 52. What could happen if you use the wrong screws in a mobile device? A) Better security B) Damage to internal components C) Faster assembly D) Improved signal Answer: B Explanation: Wrong screws can puncture or deform boards. Question 53. A customer complains their phone only charges intermittently. The most likely reason is: A) Broken battery B) Debris or damage in the charging port C) Weak Wi-Fi signal D) Corrupted firmware
Explanation: NFC enables short-range wireless communication. Question 57. If a battery voltage is below 3.0V, what should you do before attempting to power on? A) Charge externally with a controlled charger B) Reinstall the OS C) Clean the camera lens D) Replace the SIM Answer: A Explanation: Low voltage batteries should be slowly charged to avoid damage. Question 58. What is the primary danger of using cheap, low-quality replacement screens? A) Faster charging B) Poor display quality and possible device damage C) Increased Wi-Fi speeds D) Longer battery life Answer: B Explanation: Inferior screens can fail quickly or harm the device. Question 59. Why should you never short the battery terminals during testing? A) It makes testing faster B) Can cause fire, explosion, or board damage C) Cleans the connectors D) Resets the phone Answer: B Explanation: Shorting battery terminals is extremely dangerous.
Question 60. What can cause a phone to boot loop (keep restarting)? A) Weak Wi-Fi B) Corrupted software or hardware failure C) Clean charging port D) New screen Answer: B Explanation: Boot loops are often caused by software or hardware issues. Question 61. What is the main reason to use a suction cup during display removal? A) To clean the glass B) To lift the display evenly and avoid cracks C) To test the battery D) To increase brightness Answer: B Explanation: Suction cups help safely lift fragile screens. Question 62. What is the best practice after replacing a charging port? A) Test with multiple cables and chargers B) Replace the battery C) Update the OS D) Remove the SIM Answer: A Explanation: Testing ensures reliable charging and data transfer.
