Introduction: Disable the Built-in Sound Card of Raspberry Pi

By
About: Systems Administrator and Software Programmer.

Introduction

Sometimes it is useful to disable the Raspberry Pi's built-in Broadcom sound chip before installing a new USB sound card so as to make it easier to troubleshooting the new USB sound card.

Scope

This instructable will cover the following:

  • How to disable sound card
  • How to install Advanced Linux Sound Architecture (ALSA) utilities
  • Use ALSA utilities to test sound card and sound device

This instructables will NOT cover the following

  • PulseAudio
  • Open Sound System (OSS)

Specifications

My Raspberry Pi:

  • Raspberry Pi 2
  • Rasbian based on Debian Version 8.0 (a.k.a Jessie)
  • Advanced Linux Sound Architecture Driver Version k4.1.10-v7+
  • Pulse Audio and OSS are NOT installed
  • 2 speakers connected to Raspberry Pi's audio/video 3.5mm socket.

Step 1: Test That Raspberry Pi's Sound Chip Is Not Faulty

Complete the "Test sound card and speaker" instructable. This step is to eliminate the possibilty that Raspberry Pi build-in sound chip is not faulty. So that you know sound is not coming from the speaker is due to your configuration and not because of Raspberry Pi's sound card is faulty.

Step 2: Configure Linux to NOT Load Broadcom's Sound Chip

Open terminal

Create a file using vi or any text editor and save in /etc/modprobe.d

cd /etc/modprobe.d
sudo vi alsa-blacklist.conf

Enter the following line

blacklist snd_bcm2835

Save the file

reboot the machine

sudo reboot<br>

Step 3: Test That Sound Card Is NOT Detected by ALSA Native Application

Open terminal:

aplay -l

"...no soundcards found" indicates that kernel module (device driver) for broadcom chip was not loaded and the card has been disabled for all intents and purposes.