Mobile Device Liquid Damage Diagnosis and Remediation

Auto audio on: the next questions will be read aloud when you click Continue.

1. 1

   What should be done first when a liquid-exposed mobile device is still powered on?

   A Power it off and disconnect the battery as soon as safely possible B Connect a charger to test whether it still accepts power C Run processor-intensive applications to generate drying heat
2. 2

   Why should a wet mobile device not be connected to a charger for testing?

   A Charging permanently resets the liquid contact indicators B Applied power can cause shorts and accelerate electrochemical corrosion C The charger will automatically erase diagnostic information
3. 3

   The image shows blue-green crystalline deposits around exposed copper traces. What do these deposits most likely indicate?

   

   A Uncured thermal compound B Normal soldering flux from manufacturing C Copper corrosion caused by liquid exposure
4. 4

   A normally white liquid contact indicator is shown after it has turned pink-red. What can the technician conclude?

   

   A The indicator contacted sufficient moisture, but it does not reveal the full damage extent B The logic board has a confirmed short circuit C The battery must have reached thermal runaway
5. 5

   Why is saltwater exposure generally more damaging than exposure to clean fresh water?

   A Saltwater immediately demagnetizes every mobile device speaker B Dissolved ions increase conductivity and leave corrosive residue C Saltwater prevents all batteries from being disconnected
6. 6

   Why may a soldered metal shield need to be removed during thorough liquid-damage remediation?

   

   A To increase the device's wireless signal strength B To prevent the shield from resetting the operating system C To access contamination and corrosion trapped beneath it
7. 7

   Which alcohol is generally preferred for a final rinse or careful manual cleaning of a disconnected logic board?

   A High-purity isopropyl alcohol, typically 90% or higher B A 50% scented rubbing alcohol containing additives C An alcohol-based beverage diluted with tap water
8. 8

   Why are batteries, displays, cameras, and other detachable modules normally removed before a logic board is ultrasonically cleaned?

   

   A They prevent the ultrasonic cleaner from producing any sound B They may be damaged by immersion or trap cleaning solution C They cause every corrosion deposit to become magnetic
9. 9

   When is it safest to attempt powering a cleaned liquid-damaged device?

   A As soon as the visible surface looks dry B While cleaning fluid remains under the shields C After complete drying, inspection, and checks for critical shorts
10. 10

    When conductive liquid bridges energized connector pins, which process can rapidly damage the metal?

    

    A Electrolysis and ion migration B Optical refraction C Acoustic resonance
11. 11

    On a current-limited DC power supply, what does substantial current draw before the power button is pressed commonly suggest?

    A Normal completion of the operating system boot sequence B A short circuit or leakage on an always-powered rail C A properly calibrated liquid contact indicator
12. 12

    With the battery disconnected, a technician places meter probes between the battery positive input and ground. What is the main purpose of this test?

    

    A To update the battery management firmware B To measure the brightness of the display backlight C To screen the main power input for abnormally low resistance or a short
13. 13

    If preserving user data is the primary objective, which repair strategy is most appropriate?

    A Stabilize and repair the original logic board enough to retrieve the data B Replace the logic board immediately and discard the original C Perform a factory reset before examining the board
14. 14

    Why is placing a liquid-damaged phone in dry rice not a proper repair method?

    A Rice supplies excessive voltage to the battery terminals B It does not remove ionic residue or hidden corrosion beneath components C It instantly activates every internal moisture sensor
15. 15

    Which combination most strongly supports galvanic corrosion inside a mobile device?

    A Dry air, identical plastics, and no electrical contact B A powered-off display stored in a sealed dry container C An electrolyte contacting dissimilar conductive materials with an electrical path
16. 16

    Magnification reveals deeply pitted and missing pins inside a liquid-damaged board connector. What is the most reliable remedy?

    

    A Replace the damaged connector and repair affected pads or traces as needed B Cover the connector with adhesive without cleaning it C Increase charger voltage to overcome the damaged pins
17. 17

    During current-limited voltage injection, a thermal image shows one small board area heating much faster than its surroundings. What does this most likely provide?

    

    A Proof that every component in the hot area is functioning normally B A clue to the location of a shorted or leaking component or current path C Confirmation that the operating system has completed startup
18. 18

    Why should a technician photograph the board and connectors before cleaning liquid damage?

    A To increase the board's resistance to future moisture B To calibrate the phone's cameras automatically C To document corrosion, missing parts, and pre-existing damage
19. 19

    After replacing perimeter adhesive seals during reassembly, which statement is accurate?

    A The original factory water-resistance rating cannot be guaranteed without appropriate validation B The repaired device is automatically more waterproof than when new C New adhesive eliminates the need to inspect the frame for deformation
20. 20

    A cleaned device works initially but develops faults several days later. What is a likely liquid-damage explanation?

    A The cleaning permanently increased the processor's clock speed B Hidden residue or corrosion remained under shields, connectors, or component packages C The liquid contact indicators began supplying power to the board