I get the drift this has been discused ad nauseam but here goes. This is a new install of a Raspberry Pi 4B. I have it connected to Wifi, updated everything using sudo apt update, and sudo apt full-upgrade. I have the RPi main (head) hdmi connected to a tv. I started up vnc and all was fine. I used raspi-config to set the vnc resolution to 1920x1080 and the headless display to the same. As long as the TV is powered up when I boot, the vnc desktop is good. I can boot with the tv on, enable vnc, the start a vnc session to windows 11 and it is fine. I can turn off the tv, an the session remains fine.
As soon as I boot with vnc running, and the tv off, this is what I wind up with. I've tried a few things with config.txt but nothing seems to have any effect. Curiously the icons seem to be sized appropriately.
BTW if I leave vnc active, and boot the hdmi output is off, and the tv has no signal.
Here is config.txt
# For more options and information see
# http://rpf.io/configtxt
# Some settings may impact device functionality. See link above for details
# uncomment if you get no picture on HDMI for a default "safe" mode
#hdmi_safe=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 will 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
hdmi_force_mode=1
# uncomment to force a specific HDMI mode (this will force VGA)
hdmi_group=2
hdmi_mode=81
# uncomment to force a HDMI mode rather than DVI. This can make 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. 700 MHz is the default.
#arm_freq=800
# Uncomment some or all of these to enable the optional hardware interfaces
#dtparam=i2c_arm=on
#dtparam=i2s=on
#dtparam=spi=on
# Uncomment this to enable infrared communication.
#dtoverlay=gpio-ir,gpio_pin=17
#dtoverlay=gpio-ir-tx,gpio_pin=18
# Additional overlays and parameters are documented /boot/overlays/README
# Enable audio (loads snd_bcm2835)
dtparam=audio=on
# Automatically load overlays for detected cameras
camera_auto_detect=1
# Automatically load overlays for detected DSI displays
display_auto_detect=1
# Enable DRM VC4 V3D driver
dtoverlay=vc4-kms-v3d
max_framebuffers=2
# Disable compensation for displays with overscan
disable_overscan=1
[cm4]
# Enable host mode on the 2711 built-in XHCI USB controller.
# This line should be removed if the legacy DWC2 controller is required
# (e.g. for USB device mode) or if USB support is not required.
otg_mode=1
[all]
[pi4]
# Run as fast as firmware / board allows
arm_boost=1
[all]
# NOOBS Auto-generated Settings:
enable_uart=1
As soon as I boot with vnc running, and the tv off, this is what I wind up with. I've tried a few things with config.txt but nothing seems to have any effect. Curiously the icons seem to be sized appropriately.
BTW if I leave vnc active, and boot the hdmi output is off, and the tv has no signal.
# For more options and information see
# http://rpf.io/configtxt
# Some settings may impact device functionality. See link above for details
# uncomment if you get no picture on HDMI for a default "safe" mode
#hdmi_safe=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 will 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
hdmi_force_mode=1
# uncomment to force a specific HDMI mode (this will force VGA)
hdmi_group=2
hdmi_mode=81
# uncomment to force a HDMI mode rather than DVI. This can make 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. 700 MHz is the default.
#arm_freq=800
# Uncomment some or all of these to enable the optional hardware interfaces
#dtparam=i2c_arm=on
#dtparam=i2s=on
#dtparam=spi=on
# Uncomment this to enable infrared communication.
#dtoverlay=gpio-ir,gpio_pin=17
#dtoverlay=gpio-ir-tx,gpio_pin=18
# Additional overlays and parameters are documented /boot/overlays/README
# Enable audio (loads snd_bcm2835)
dtparam=audio=on
# Automatically load overlays for detected cameras
camera_auto_detect=1
# Automatically load overlays for detected DSI displays
display_auto_detect=1
# Enable DRM VC4 V3D driver
dtoverlay=vc4-kms-v3d
max_framebuffers=2
# Disable compensation for displays with overscan
disable_overscan=1
[cm4]
# Enable host mode on the 2711 built-in XHCI USB controller.
# This line should be removed if the legacy DWC2 controller is required
# (e.g. for USB device mode) or if USB support is not required.
otg_mode=1
[all]
[pi4]
# Run as fast as firmware / board allows
arm_boost=1
[all]
# NOOBS Auto-generated Settings:
enable_uart=1
Statistics: Posted by Brodan — Sun Feb 15, 2026 6:11 pm — Replies 8 — Views 87