CompTIA A+ Core Certification: The Basics of Hardware and Network Troubleshooting - Mobile Device Troubleshooting

220-1101: Objective 5.5: Given a scenario, troubleshoot common issues with mobile devices.
With more organizations than ever using laptops, tablets, and smartphones, it is important to know how to troubleshoot devices on the go. You need to understand the concepts covered in the following sections for the 220-1101 exam and to improve your technical skills.

Poor Battery Health and Improper Charging
To fix a battery that is not charging on a tablet or smartphone, do the following:
- Make sure the charger is rated for the tablet or smartphone. Chargers are rated in amperage (1A = 1000mA). A minimum of 500mA is needed to charge a smartphone (but 1A is much faster), and a minimum of 2.1A is needed to charge a tablet.
- Check the charging port on the device. Pocket lint can make for a faulty connection on a phone. Laptop charging ports are also susceptible to dust and debris.
- If the charger has a toggle for iOS and non-iOS devices, choose the correct setting for your device.
- If you use a USB port on a laptop or desktop computer, enable USB fast charging if it is available on the computer, and be sure to use that port.
- You cannot charge a smartphone from an unpowered USB hub; it has only 100mA available per port.
- Ordinary USB ports cannot charge a device when the computer is asleep.
If you have checked these issues with no success, replace the cable. If a known-working cable does not help, replace the battery or have the unit serviced.

On a laptop, if the system works when plugged into AC power but not on battery power, check the following:
- Make sure the battery is installed properly.
- Wipe off any corrosion or dirt on the battery and laptop battery contacts.
- Determine whether the battery can hold a charge. Make sure that the battery is properly installed and that the AC adapter has proper DC voltage output levels. Leave the system plugged in for the recommended amount of time needed to charge the battery; then try to run the system on battery power. If the battery cannot run the system, or if the system runs out of battery power in less than an hour, replace the battery. If replacing the battery does not solve the problem, the laptop needs to be serviced or replaced.
- If the battery is hot after being charged or has a warped exterior, replace it.

Various factors can still cause extremely short battery life. Check the following:
- Do not overcharge a device’s battery.
- For best results, do not wait until a device is almost out of power to charge it.
- Adjust the screen brightness to the lowest level that is comfortable to use.
- On iOS devices, turn off background app refresh.
- Upgrade to the latest OS or OS updates available for your device.
- Use a phone battery helper app to manage charging, but do not run other apps while the device is charging.
- Close apps from the iOS App Switcher.
- Shut down an iOS device weekly with the slider switch.
- On devices that use AMOLED displays, switch to black wallpaper (theme), to save power.
- Extreme cold can quickly sap a device’s battery, so be sure that the user takes in climate considerations and keeps the device as warm as possible in cold climate use.

Swollen Battery
A swollen battery is most likely the result of overcharging. In addition to replacing the battery, check the AC adapter to make sure it is putting out the correct voltage. If the case is bulged (from the battery or for any other reason), the device is likely unusable. Check for warranty information and arrange for replacement.

Broken Screen
A broken screen on a phone or tablet takes some specialty repair tools and skills, but the problem is common enough that toolkits and screen repair services are available in most areas.
A broken screen cannot be fixed, but it can get worse, so replacing the screen as soon as possible is important. An unrepaired screen can get worse with use, allowing dust and moisture into the device.
If immediate repair is not possible, at least cover the screen with a plastic screen protector, to keep it together until repairs can be made.
Screen repair kits are available online, and they have accompanying YouTube tutorials. Still, sending the device out for repair might be more economically prudent.
Some carrier contracts have insurance available. If the device is insured, contact the carrier or vendor to get a replacement or upgrade, whichever is appropriate.
After the device has been replaced or repaired, consider the likelihood that it will be dropped and broken again. If the device is often exposed to hazardous use, buy a plastic cover for the screen to prevent or minimize the cracks before the next incident.

Poor/No Connectivity
Most laptops have a pushbutton, pressure-sensitive touch button or an Fn key combination to use to enable or disable Wi-Fi networking. If there is no wireless connectivity, press the button or use the Fn key combination to enable the connection. Most laptops display an indicator light when the connection is enabled.
Late-model laptops, tablets, and smartphones have an airplane mode that disables all onboard radios (Wi-Fi, Bluetooth, and cellular) when enabled. Turn off airplane mode and try the connection again. Wi-Fi can also be disabled separately from airplane mode. Check the Settings menu and enable Wi-Fi, if necessary.
On Windows devices, if the connection fails, check the Wi-Fi connection in the notification area. You might need to reconnect manually. If no Wi-Fi connection indication appears, open the Device Manager and check the Network Adapters category. If the Wi-Fi adapter is not listed, rescan for hardware changes.
If Device Manager cannot locate the Wi-Fi adapter, shut down the system, disconnect it from all power sources, and open the access panel to the Wi-Fi card. If the card is loose, reconnect it and retry the connection after restoring power and restarting the computer. If the Wi-Fi antenna wires are loose, tighten them.
Some tablets and smartphones have intermittent wireless if the Wi-Fi signal is very weak. Switch to a cellular data connection (if available) until a stronger Wi-Fi signal is available.
Change the angle of your laptop or two-in-one device screen, or turn the entire unit to help improve Wi-Fi reception; these units have their antennas in the screen.
Use the signal strength indicator to find the strongest wireless signal that can be used. In a public setting, two or more open networks might be available.
 

Liquid Damage
The problem with device mobility is that devices get taken places they should not—specifically, near water. Dropping a phone into a stream, lake, or hot tub while taking vacation pictures, or dropping it into a toilet or sink while in a bathroom exposes the phone to potentially terminal liquid exposure. If a device takes an unintentional bath, these steps could save the device if the exposure was minimal:

Step 1. Be quick in getting the phone out of the water. Every second counts, and any delay greatly reduces the chance of recovery. If the device was plugged into anything, remove it from the power source and then unplug the device. Power off the device, if necessary. Any other attachments, such as battery packs and memory cards, should come out as well.
Step 2. Dry off the device with a towel, and shake any water you can out of the ports.
Step 3. Do what you can to dry it out. A few different ways accomplish this, and because time is of the essence, using what is available is the best choice.

A common method is adding cat litter or rice to a container large enough to hold the device, to hopefully draw moisture out of the phone. Some argue that rice might do some damage, but it is usually the most available option. Put the device into the container, cover it with the ports facing down so they can drain, and seal the container to increase effectiveness.

A day or two in the container will get the water out, but only then can the device be tested to see if it survived the soaking. If it will not power up, you might need to seek out a pro who can disassemble it and check inside.

Overheating
Overheating is a dangerous symptom that should be addressed as soon as it is discovered. Heat comes from the processor, but unlike with desktop computers, there is no fan to move the air away. Room-temperature air flow around a device should keep it in a normal range, but if a device is running hot, do not ignore it. Consider these causes:
- Is it stored in an enclosed space, such as a warm pocket or under a blanket? Air needs to be able to flow around it to keep it cool.
- Sometimes the CPU is working too hard and needs a rest. This can result from too many apps open and running, or maybe from an app that needs updating. Wi-Fi and Internet use also place heavy demands on a device’s CPU.
- Some phone and tablet cases restrict air flow and can cause heat to be retained. If the phone is warm, remove the case and let it breathe.
- Left in the sun, especially under glass (such as in a car), the air can get too hot to allow the device to cool.
- The battery could be failing and causing excess heat. If battery swelling occurs, shut off the device and replace the battery. With any luck, the battery compartment will not be damaged. Sometimes heat is an early warning for a bad cable or charger. If so, replace the charger and/or cable.

The best treatment for an overheated phone is to shut it down, remove the cover, and give it a rest in a cool place. Some people put the device in a refrigerator, but that is not necessary—in fact, depending on the cleanliness of the fridge, it can cause its own problems. Room temperature is fine if the device is powered down and the cover is removed. If the problem continues, review the items in the preceding list and troubleshoot.

Digitizer Issues
A touchscreen display differs from a standard laptop display because it has a digitizer layer on top of the display panel. The digitizer detects and transmits touches to the laptop processor. Digitizers are also used on touchscreen smartphones, tablets, fitness monitors, smart watches, phablets, e-readers, and smart cameras.
If the digitizer layer is damaged but the display panel is intact, the digitizer layer can be replaced separately.

Note: For examples of pricing and availability of digitizers, see https://touchscreendigitizer.net.

Nonresponsive Touchscreen
The most common reason for a nonresponsive touchscreen is dust, dirt, and grease on the surface. To clean it, use an antistatic wipe or spray designed for touchscreens.
Dry hands might not work well with touchscreens. Gloves without special fingertips also cannot use a touchscreen.
To determine whether the touchscreen has failed, try a stylus made for the touchscreen. Reset the device and retry. If the touchscreen is still not responsive, have the unit serviced.

Physically Damaged Ports
Mobile devices have few ports, compared to a laptop or PC, but because of the harsh environment for mobile phones and tablets, problems can still occur.
 

One typical harsh environment for a mobile device is the user’s pocket. Pocket storage of a phone invites pocket lint to invade the ports. If charging becomes difficult, the first place to look is in the charging port to see if the contacts are visible. Clean the port with a wooden toothpick—take care to lightly scrape and remove dust until the contacts are clean. Do not use a metal pick from a PC toolkit for this because it can easily damage the contacts.
USB ports on some phones (Android, for example) can come out of alignment. If this happens, remove the battery and use a soft wooden toothpick to carefully realign USB ports.
Humidity is another concern for some phone users. Liquids and phones do not mix, so users who live in rainy or humid climates can have corrosion issues over time. Use in steam rooms or around hot tubs can expose phones to excessive humidity as well. If these uses are expected, a waterproof phone or case is a good idea.
Users can prevent corrosion, but only a professional can cure it. Fixing this problem with proficiency takes practice.

Malware
Just as malware can infect users on a network, mobile devices are subject to malicious software designed specifically to disrupt mobile operating systems. Examples are similar to the security issues facing PC users, but customized for the mobile device. They include phishing, Trojans, spyware, and adware (called madware on mobile phones).

Steps to protect against mobile malware are similar to any security steps:
- Install security software.
- Keep the OS and applications current, to enable the latest security updates.
- Use apps vetted by app stores that your provider recommends.
- Protect against loss and theft by enabling Find My Phone settings and screen-locking settings.
 

Cursor Drift/Touch Calibration
Cursor drift can be caused by accidentally swiping or pressing on the device’s touchpad, or by encountering a problem with the device’s integrated pointing stick. If you are using a mouse, disable the touchpad or change its sensitivity settings to ignore accidental touches.