The default sound output is HDMI, which can be changed to 3.5 audio ports.
Command
$:sudo amixer cset numid=3 1
Config file is set up with HDMI Direct connect monitor, play movie, music 3.5 mouth no sound
Raspi-config set from 3.5 output no sound
There's no way out.
# For more options and information see
# HTTP://WWW.RASPBERRYPI.ORG/DOCUMENTATION/CONFIGURATION/CONFIG-TXT.MD
# Some settings may impact device functionality. See link above for details
# uncomment if get no picture on HDMI for a default "safe" mode
#hdmi_safe =1
# Uncomment this if your display have a black border of unused pixels visible
# and your display can output without overscan
#disable_overscan =1
# Uncomment the following to adjust Overscan. Use positive numbers if console
# goes off screen, and negative if there is too much border
#overscan_left =16
#overscan_right =16
#overscan_top =16
#overscan_bottom =16
# Uncomment to force a console size. By default it'll be display ' s size minus
# overscan.
#framebuffer_width =1280
#framebuffer_height =720
# Uncomment if HDMI display is not detected and composite is being output
#hdmi_force_hotplug =1
# Uncomment to force a specific HDMI mode (this would force VGA)
hdmi_group=2
Hdmi_mode=14
# Uncomment to force a HDMI mode rather than DVI. This can do audio work in
# DMT (computer monitor) modes
#hdmi_drive =2
# Uncomment to increase signal to HDMI, if you have interference, blanking, or
# no display
#config_hdmi_boost =4
# Uncomment for composite PAL
#sdtv_mode =2
#uncomment to overclock the arm. The-MHz is the default.
#arm_freq =800
# NOOBS auto-generated Settings:
#hdmi_force_hotplug =1
Config_hdmi_boost=4
#overscan_left =24
#overscan_right =24
#overscan_top =16
#overscan_bottom =16
Disable_overscan=1
Raspberry Pi Sound Settings