Device will not respond
Sometimes the android software the device runs will stop being responsive to finger taps and input. An easy fix is to turn the device off and on again. If the problem persists it may be an issue with a certain app or the android operating system itself. If the device becomes unresponsive only in a specific app then the application is likely the culprit, otherwise you may need to update or restore the device due to software issues. If these options fail the device may have suffered some form of physical damage and may need parts like the motherboard replaced.
Device is running slow
If the device is too slow to load applications then it may be because there is a virus or a malicious application on your device eating up resources. In order to resolve this issue you have to options: booting the device into safe mode or completely restoring the device.
Booting into safe mode
In order to boot into safe mode press and hold the volume down; once the logo appears stop pressing the power button and keep pressing the volume button. If you succeeded safe mode will be displayed in the bottom corner and all 3rd party apps will be disabled allowing you to remove the potential malicious software.
Booting into recovery mode
If all else fails and your device still is abnormally slow and freezes you might need to boot into recovery mode and restore the device. In order to do this you need to press the power button, the volume up button and the home button. Once the phone vibrates, release the power key but continue holding the other keys.
Restoring the device
Once you boot into recovery mode you can wipe the cache partition and this may fix device slowness and unresponsiveness. However you may need to go on with a factory restore. To do this, boot into recovery mode and volume down to wipe data/factory reset.
Device having difficulty connecting to wireless internet
Sometimes, the phone will be slow to connect to wireless internet, or fail to connect entirely. This can be caused by either a glitch in the phone itself, or the device being too sensitive in evaluating signal strength. The first troubleshooting step to take is to try to restart the device and reconnect. If the problem persists, your problem may be one of the following issues:
Wi-Fi not turning On
You may need to attempt a cache reset on your phone, instructions for doing so can be found at this guide page. If that does not resolve the issue, you may need to restart your phone or perform a full factory reset. If the restart does not resolve the issue, be sure to backup your information before performing a reset. If those steps do not resolve the issue, it is likely a hardware or firmware problem.
Wi-Fi constantly disconnecting and reconnecting
Start the phone in safe mode and check to see if you have installed an application that may be causing the problem. If the problem does not occur while in safe mode, then it is likely an app you have installed. Find what app it is and uninstall it. If that does not work, try wiping the cache partition while in recovery mode. If the problem persists, back up your phone data and do a full factory reset.
Device battery dies prematurely
Premature battery death can be a symptom of multiple problems, such as too many application being open at once, a faulty charger, or a battery past its useful lifespan. Solving this issue depends on which issue is the underlying problem.
'Cleaning up device apps
The easiest of the 3 would be to ensure that you go to the Task manager (by tapping the square button on the home row) and then tapping the “Clear All” button. This will stop all currently running apps in memory and free up resources on your phone. Also ensure that any wireless services you have turned on (such as Bluetooth, GPS, and NFC) are actually in use, and turn them off when done using that particular service. Look through your app list to uninstall any unneeded apps, as these apps may start themselves up in the background and shorten your battery life.
Checking device charger
'If the first solution does not fix your problem, then ensure that your charger is functioning correctly. Try borrowing a friends charger (check both the charger and power brick) and see whether the device charges faster and keeps the charge longer.
'Replacing the device battery
If that diagnostic fails to produce any results, then it most likely is a result of the battery outliving its usefulness. In this case you must order and replace the battery of your device.
SD Card Won’t Connect
If your device fails to recognize the SD card, it can mean that one of the following has happened: the SD card has been corrupted by malware or a virus, the SD card has been damaged (note: older generation SD cards tend to be of poorer quality), or that the device itself has a hardware issue rather than the SD card. In order to test the card itself, simply remove it from your device and insert it into a known, working device. If the second device doesn’t recognize the card, you will need to replace the SD card. If the card works, the issue is with the device itself.