5.5 - Troubleshooting Mobile Devices Flashcards
Poor battery health
Replace aging battery
– There’s only so many recharges
Bad reception
– Always searching for signal
– Airplane mode on the ground
Disable unnecessary features
– 802.11 wireless, Bluetooth, GPS
Check application battery usage
– iOS and iPadOS: Settings/Battery
– Android: Settings/Battery
Swollen battery
Buildup of gas
– Designed to self-contain
– Do NOT open the battery packet/container
– Significant fire risk
– You’ll be sorry
Faulty battery
– Stop using immediately
– Dispose of properly
Device can be damaged
– Better than having a fire
Broken screen
Time for a backup - Do this first!
Replace the screen - No easy fixes
The glass is sharp
– Screen protectors can help
– Use clear tape until repaired
Improper charging
Check everything in the charging process
– Cables, interfaces
Check the cable interface
– Remove any obstructions
Check the cable
– Don’t use frayed or damaged cables
– Try a known-good cable
Verify the power adapter
– Check with a multimeter
Poor/no connectivity
Cellular or Wi-Fi
– Location, location, location
Cellular
– Signal strength
– Location matters
– Outdoor connectivity may be better
Wi-Fi
– Limited range
– Interference can limit throughput
– May need a channel/frequency configuration change
Liquid damage
Many phones have a Liquid Contact Indicator (LCI)
– Turns color when liquid has been present
Power down the phone
– Don’t power it back on. Don’t do it.
Remove the case, cards, back, and battery
– If possible
Putting the phone in a bag of rice doesn’t
actually work very well
– Silica gel is better
Leave it alone
– Don’t turn it on
– Do not charge the phone
– Don’t connect it to power
– Don’t press any keys
– Don’t heat the phone
– Don’t move it around
Wait at least a day
– Or until the phone appears to be dry
– And then perhaps a few hours after that
Once you’re sure, power it on
– Hope for the best
Overheating
Phone will automatically shut down
– Avoid overheating damage
Charging/discharging the battery, CPU usage,
display light
– All of these create heat
Check app usage
– Some apps can use a lot of CPU
Avoid direct sunlight
– Quickly overheats
Digitizer issues
Touchscreen completely black or
not responding to input
– Screen presses do not register
Apple iOS reset
– Press power button, slide to power off,
press power button
– Hold down power button and Home|Volume
for 10 seconds
Android device restart
– Remove battery, put back in, power on
– Hold down power and volume down until restart
– Some phones have different key combinations
– Some phones do not have a key-based reset
Physically damaged ports
External interface - Charging and data transfer
Rough handling and accidents
– Damages the interface
Not charging - Look closely
Not modular - Requires a system board replacement
Malware
Always a concern
– Even on mobile devices
– The device type doesn’t matter
Look for symptoms
– Unusual apps, large data transfers, pop up messages,
high CPU usage, device overheating, excessive
battery use
Try a security app or scanner
– Identify malware infections
Cursor drift
Random input or cursor moves without
touching the device
– Common on older screens
Use a touch calibration app
– Requires user input
– Touch certain areas of the screen
The system will adjust to the new calibration parameters
– No more drift
