I have a new Rpi4 and have connected 2 x 7" HDMI displays.
When I first booted up with both screens, it wouldn’t detect them after boot until I unplugged the HDMI cables and replugged them back in and then the GUI would display.
I then followed the instructions that came with the displays to install the 1024x600 driver and then it booted up ok, but only one display would be detected by the GUI.
I did notice however, that i have one python script that i can run that will run the Omxplayer and output video on a selected HDMI and this seems to work for both displays.
So my issue seems to be with the Raspian Buster GUI not detecting multiple displays after installing the display driver.
Any help would be appreciated.
Below is the config.txt file after the drivers were installed:
For more options and information see
Some settings may impact device functionality. See link above for details
uncomment if you get no picture on HDMI for a default “safe” mode
uncomment this if your display has a black border of unused pixels visible
and your display can output without overscan
uncomment the following to adjust overscan. Use positive numbers if console
goes off screen, and negative if there is too much border
uncomment to force a console size. By default it will be display’s size minus
uncomment if hdmi display is not detected and composite is being output
uncomment to force a specific HDMI mode (this will force VGA)
uncomment to force a HDMI mode rather than DVI. This can make audio work in
DMT (computer monitor) modes
uncomment to increase signal to HDMI, if you have interference, blanking, or
uncomment for composite PAL
#uncomment to overclock the arm. 700 MHz is the default.
Uncomment some or all of these to enable the optional hardware interfaces
Uncomment this to enable the lirc-rpi module
Additional overlays and parameters are documented /boot/overlays/README
Enable audio (loads snd_bcm2835)
hdmi_cvt 1024 600 60 6 0 0 0