B3+ will not output composite video #7140
Description
Describe the bug
I have tried 3.16.9, 3.22.2 aarch64 with the latest firmware packages and I have tried the latest 32 bit raspberry release https://downloads.raspberrypi.com/raspios_lite_armhf/images/raspios_lite_armhf-2025-10-02/2025-10-01-raspios-trixie-armhf-lite.img.xz
Nothing I do will produce either the rainbow splash screen or any other screen on the BNC connector.
I have verified that I have a good connection from the center of conductor to the middle pin on the BAV99 protection diode and that the shield connects to ground. I have a bare TRRS connector, and these pins ohm out correctly.
Steps to reproduce the behaviour
Install one of the several installs above.
in config.txt or usercfg.txt, set these:
dtoverlay=vc4-kms-v3d,composite
sdtv_mode=0
sdtv_aspect=1
hdmi_ignore_hotplug=1
#hdmi_force_hotplug=1
Connect NTSC monitor.
Boot
Observe there is no rainbow screen or any other video activity on the NTSC monitor.
Device (s)
Raspberry Pi 3 Mod. B+
System
System Information
Raspberry Pi 3 Model B Plus Rev 1.4
PRETTY_NAME="Raspbian GNU/Linux 13 (trixie)"
NAME="Raspbian GNU/Linux"
VERSION_ID="13"
VERSION="13 (trixie)"
Raspberry Pi reference 2025-10-01
Generated using pi-gen, https://github.com/RPi-Distro/pi-gen, 7385adde4cd7a2bfcf6e6ef0e5b790391c172a8d, stage2
Linux raspberrypi 6.12.47+rpt-rpi-v7 #1 SMP Raspbian 1:6.12.47-1+rpt1 (2025-09-16) armv7l GNU/Linux
Revision : a020d4
Serial : 0000000032fedd68
Model : Raspberry Pi 3 Model B Plus Rev 1.4
Throttled flag : throttled=0x0
Camera : supported=0 detected=0, libcamera interfaces=0
Videocore information
Aug 20 2025 17:04:09
Copyright (c) 2012 Broadcom
version cd866525580337c0aee4b25880e1f5f9f674fb24 (clean) (release) (start)
alloc failures: 0
compactions: 0
legacy block fails: 0
Filesystem information
Filesystem 1K-blocks Used Available Use% Mounted on
udev 333120 0 333120 0% /dev
tmpfs 188628 3456 185172 2% /run
/dev/mmcblk0p2 7080136 2615656 4140824 39% /
tmpfs 471560 0 471560 0% /dev/shm
tmpfs 5120 12 5108 1% /run/lock
tmpfs 1024 0 1024 0% /run/credentials/systemd-journald.service
tmpfs 471564 0 471564 0% /tmp
/dev/mmcblk0p1 522230 90970 431260 18% /boot/firmware
tmpfs 1024 0 1024 0% /run/credentials/serial-getty@ttyS0.service
tmpfs 94312 8 94304 1% /run/user/0
Display Information
Running (F)KMS, console
/sys/class/drm/card0-Composite-1
/sys/class/drm/card0-HDMI-A-1
config.txt
aphy_params_current=819
arm_boost=1
arm_freq=1400
arm_freq_min=600
audio_pwm_mode=514
auto_initramfs=1
camera_auto_detect=1
config_hdmi_boost=5
core_freq=400
desired_osc_freq=0x331df0
desired_osc_freq_boost=0x3c45b0
disable_commandline_tags=2
disable_fw_kms_setup=1
disable_l2cache=1
disable_overscan=1
display_auto_detect=1
display_hdmi_rotate=-1
display_lcd_rotate=-1
dphy_params_current=547
dvfs=3
enable_tvout=1
enable_uart=1
force_eeprom_read=1
force_pwm_open=1
framebuffer_ignore_alpha=1
framebuffer_swap=1
gpu_freq=300
hdmi_enable_4kp60=-1
init_uart_clock=0x2dc6c00
initial_turbo=60
lcd_framerate=60
mask_gpu_interrupt0=3072
mask_gpu_interrupt1=26370
max_framebuffers=2
over_voltage_avs=45000
over_voltage_avs_boost=0x249f0
pause_burst_frames=1
pciex4_reset=1
pmic_turbo_threshold=600
program_serial_random=1
sdram_freq=450
sdtv_aspect=1
total_mem=1024
hdmi_force_cec_address:0=65535
hdmi_force_cec_address:1=65535
hdmi_ignore_hotplug:0=1
hdmi_pixel_freq_limit:0=0x9a7ec80
device_tree=-
overlay_prefix=overlays/
hdmi_cvt:0=
hdmi_cvt:1=
hdmi_edid_filename:0=
hdmi_edid_filename:1=
hdmi_timings:0=
hdmi_timings:1=
cmdline.txt
coherent_pool=1M 8250.nr_uarts=1 snd_bcm2835.enable_headphones=0 cgroup_disable=memory snd_bcm2835.enable_headphones=1 snd_bcm2835.enable_hdmi=1 snd_bcm2835.enable_hdmi=0 vc_mem.mem_base=0x3ec00000 vc_mem.mem_size=0x400000
00 console=ttyS0,115200 console=tty1 root=PARTUUID=0be25151-02 rootfstype=ext4 fsck.repair=yes rootwait
/sys/class/drm/card0-Writeback-1
Connector 0 (33) HDMI-A-1 (disconnected)
Encoder 0 (32) TMDS
Connector 1 (51) Composite-1 (unknown)
Encoder 1 (50) TVDAC
Crtc 3 (107) 720x480i@59.94 13.500 720/16/64/58/- 480/6/6/33/- 60 (59.94) P|D
Plane 3 (96) fb-id: 680 (crtcs: 3) 0,0 720x480 -> 0,0 720x480 (XR24 AR24 AB24 XB24 RG16 BG16 AR15 XR15 RG24 BG24 YU16 YV16 YU24 YV24 YU12 YV12 NV12 NV21 NV16 NV61 RGB8 BGR8 XR12 AR12 XB12 AB12 BX12 BA12 RX12 RA12)
FB 680 720x480 RG16
Connector 1 (51) Composite-1 (unknown)
0 720x480i@59.94 13.500 720/16/64/58/- 480/6/6/33/- 60 (59.94) P|D
1 720x576i@50.00 13.500 720/12/64/68/- 576/5/6/38/- 50 (50.00) D
2 720x288@50.08 13.500 720/20/64/60/? 288/2/3/19/? 50 (50.08) D
3 720x240@60.05 13.500 720/14/64/60/? 240/3/3/16/? 60 (60.05) D
---- A billion plane lines here ----
Logs
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Additional context
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