I have an older TV that does not support 1080p. I can't seem to get any picture on it. Initially I tried connecting my already built libreelec box on a RPi 3, but the TV displayed an error message. I then tried doing a fresh libreelec install v11 (maybe I should try v10?). Same result. I see the initial rainbow splash screen, but then the screen goes black and the TV eventually displays an error message that it can not display the picture.
I tried forcing 720p using config.txt and hdmi_mode=4
I also tried hdmi_safe=1
no luck with either....
how can I get libreelec to boot into a lower resolution initially and then I can make adjustments from there?