How can I troubleshoot the audio system on my Audi A4?

I recently purchased a used Audi A4 and the audio system seems to be having issues. Whenever I try to play music, either through Bluetooth or a USB, there is no sound coming out of the speakers. I have checked the volume settings and made sure the connections are secure, but the problem persists. How can I go about fixing this issue?

It's possible that there could be an issue with the speakers themselves. Have you tried connecting a different device or using a different source to see if the problem persists? If the issue only occurs with one specific device, it could be a problem with that device's audio output. If it happens with all devices, then it could be an issue with the speakers.

Another possibility is that there could be a problem with the audio settings on your Audi. Try accessing the audio settings and make sure they are set correctly for the source you are using. If you are unsure, you can also try resetting the audio system back to its factory settings.