Swipe down twice from the top of your phone screen to check if the Wi-Fi or mobile data icon is on. Check the Status Bar on top of your phone screen to check the signal strength of your Wi-Fi or mobile data connection.

Restart your phone by pressing and holding the Power Key. If the problem remains, contact an authorized repair center or customer service for assistance.

Remove applications running in the background. Tap on Recent to switch around running apps and select the ones to be removed. Swipe all the way to the left and tap CLEAR ALL. Turn off Location (GPS), Bluetooth or Hotspot when not in use.

Swipe down twice from the top of your phone screen to show the Bluetooth icon and see if it is on. Make sure your device is close to your phone.

It is normal that your phone heats up when you play games, talk on the phone, watch videos, run apps requiring large memory or use your phone as a Wi-Fi hotspot.

Check the volume of your phone by using the Volume Up/Down Key on the side of your phone. If your phone is not in mute but you hear no sound when playing music or streaming video, restart your phone.

There are some possible causes with their respective ways to solve. Some SMS/MMS messages may take up large storage space in your phone. Clean up files to have the available storage space.

The USB port on your computer might not be working. Try another USB port. If the problem remains, try restarting your computer. The USB cable is non-functional. Check the list of your computer programs to see if USB driver is installed.

Make sure you are using a functional cable or adapter. Try to use a different one that meets the specified standards by your telecom service provider or manufacturer and see if your phone shows charging signs.

Restart your phone. Press and hold the Power Key, and tap Restart. You might have triggered Accessibility feature unintentionally. Press both Volume Up and Volume Down keys to exit Accessibility feature.

The Federal Communications Commission (FCC) has defined standards for wireless mobile devices to be compatible with hearing aid instruments. The current standard is set by American National Standard Institute (ANSI). The HAC standard adopts a M/T rating system. The "M" rating indicates the reduced interference with hearing aids that operates in acoustic mode, such as on a microphone. The "M" rates from M1 to M4, with M4 being the best. The "T" rating specifies the capability of the wireless mobile devices in operating with hearing aids that integrates a telecoil (a small copper wire inside hearing aid that converts sounds into electromagnetic signals) and operates in inductive coupling mode. The "T" rates from T1 to T4, with T4 being the best. The ratings are not a guarantee. However, it is suggested to choose a wireless mobile device with at least "M3" in the M rating and "T3" in the T rating to ensure wide compatibility with hearing aid instruments.