Troubleshooting • Re: Pi HDMI CLI changes to huge font after few hours

the KMS driver ignores all video settings in config.txt - video mode changes made to this file will have no effect !
(see this: https://www.raspberrypi.com/documentati ... splay-mode)

NOTE: this assumes an updated Bootloader (PI4/400/5). if you are not sure, update it... instructions here:
https://www.raspberrypi.com/documentati ... ate_stable

- check your HDMI cabling and EDID status:
power off your PI
remove the SD card
power on the pi.
- you should get the diagnostic display as shown below. Pay attention to the EDID data status (the last line "display"... below says EDID=OK)
if you do not get the diagnostic display, it may be your cabling or an adapter? - check your cabling

however, you can set the resolution manually:
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)

Statistics: Posted by terribleted — Sun Sep 14, 2025 7:19 pm

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