Ill try this in the morning.power off, remove the SD card, power up
you should get the diagnostic display. pay attention to the "EDID" data lines... if both monitors do not say "EDID=ok" then it's possible the second monitor is not sending EDID data back to the PI. without this data, the PI does not know what resolution to set, so it sets none.
below is how to set resolution for screen 1, i assume screen 2 would be similar, but i don't have the exact incantation.
in /boot/cmdline.txt (add to the front/end of the line, NOT a new line)
-- IMPORTANT NOTE: for Bookworm, the file is at /boot/firmware/cmdline.txt !!
video=HDMI-A-1:1024x768@60D
(or whatever resolution you want)
maybe the second display is HDMI-A-2 ???
The interesting thing is that both monitors were working on the previous install of raspian on the same sd card. The monitors still both work fine with other computers (they are both connected to hdmi switches) so by a process of elimination the issue is with this new install of raspian.
Statistics: Posted by Mczakk — Sat Jan 27, 2024 11:49 pm
