24 Jul 2017, 11:55

Voici le /boot/config.txt venant d'un de mes rpi connecté en composite sur un crt.

# uncomment if you get no picture on HDMI for a default "safe" mode
#hdmi_safe=1

disable_overscan=1

# uncomment to force a specific HDMI mode (this will force VGA)
#hdmi_group=1
#hdmi_mode=1

# comment to get jack audio
#hdmi_drive=2

# Using /etc/modules is deprecated and no longer supported on 4.4 kernel
# So manually enable audio
dtparam=audio=on

#config_hdmi_boost=0

# force hdmi while the tv can take time before sending the signal on the hdmi output
#hdmi_force_hotplug=1

# uncomment for composite PAL
sdtv_mode=2
hdmi_ignore_hotplug=1

# uncomment for lirc-rpi
#dtoverlay=lirc-rpi

# if you plug your tv at the same time as your rpi and that the rpi switches from the hdmi or give a low resolution because tv had no enough time to initialize it
boot_delay=3

# uncomment if you don't want the rainbow at startup
disable_splash=1

# Overclock
gpu_mem_256=128
gpu_mem_512=256
gpu_mem_1024=512

avoid_safe_mode=1

Ligne 22, commentes config_hdmi_boost=0 et reteste.