If this issue occurs during a call:
a) Move to a location with a stronger signal or less interference to improve the quality of the call. This is normal and does not indicate a problem with your device.
b) Try making calls with a headset to see whether call quality is improved. If call quality is improved, the microphone or receiver may be damaged. Back up your data and take your device and proof of purchase to our repair center to get more professional technical assistance.
c) Check the hardware state by accessing “Support Center”->“Hardware diagnosis”-> “START TESTING” ->Authorize the permissions required for diagnostics->Follow the instrutions to test, especially to verify that the “Microphone” works. If there is a hardware issue, back up your data and take your device and proof of purchase to our repair center to get more professional technical assistance.
a) Try to press the volume up key to increase call volume
b) Check whether the mute mode is active, touch to disable it.
c) Try making calls to another phone to check whether it is a problem with your device.
If this issue occurs when playing music or video:
a) Your device’s audio may be poor because of a poor network connection. Enable Airplane mode for a few minutes, then disable it and check your network connection again. Alternatively, move to a location with a better network connection.
b) Open the camera on your device and record a video. Open and play the recorded video.
If the sound is normal when playing back the video, it means the speaker of your device is working normally.
Try to reset or update your device. (Refer to Q How can I perform a factory reset on my phone & Q How can I upgrade my device).
If the previously described options do not help, you can contact our hotline or repair center to get more professional technical assistance. Find the hotline or repair center information from the TCL website or APP “Support Center”.