Display problem

[arpanet999]

What were you doing?

So i have just installed FullPageOS on a Raspberry PI 3B
Everything works on my computer screen. Like it is supposed to.
Then i move it to another location with another screen.
i see the Boot process. The logo shows and all. and when the kiosk mode is suppose to happend it just goes black. Not even the mouse is there. It has network trough cable. same cable as before so no problem there. i have tryed connect to wifi but nothing. When i reconnect to the first screen it works but movint it to the other screen a couple meters away then that problem occurs.
Its an Samsung S32A600UUU S60a 32" QHD VA 16:9 2560x1440 screen.

Version of FullPageOS?

i took this one from you mirror.
2021-04-14_2021-03-04-fullpageos-buster-armhf-lite-0.12.0.zip

[Cenedd]

Had this on the latest Pi4's I deployed. Previous ones no problem at all but the latest went black as soon as it went to GUI. You sometimes got a flash of the FullPageOS logo before it went black but not always. I can't speak for the 3B but I got it sorted on my 4's.

1. Do bootload update of Pi via Pi Imager > Misc Utility Images > Bootloader > SD Card Boot

2. Install FullPageOS using Pi Imager and make sure to enable SSH in the options. I'm using Nightly 2022-10-28 as I found that the more recent 22-11-01 offered in Pi Imager doesn't start X Windows - at least not when this issue occurs. With 22022-10-28 it does, you just can't see it! but you can VNC in and see that it's working.

3. Boot Pi, wait for display to fail and then SSH in over the network

4. switch to admin mode:
   sudo su

5. Edit config.txt (nano /boot/config.txt) to uncomment/change these lines. Mode 82 is 1920x1080 so you may want to change that for your display. You can look the modes up here: https://www.raspberrypi.com/documentation/computers/config_txt.html#video-options

   hdmi_force_hotplug=1
   hdmi_group=2
   hdmi_mode=82
   config_hdmi_boost=4
   

6. Update all packages using following commands:
   sudo su
   apt update
   apt upgrade -y
   shutdown now

7. Cold boot it and it should work - well, if it were a Pi4 at least!

Good luck!

[guysoft]

@Cenedd do you think its worth to add this in to the wiki? Any idea under what category?

[Cenedd]

Definitely, yes. Under 'Assorted Guides'? There didn't seem to be much on the issue from any source other than setting HDMI safe mode. That does work with straight Raspbian but it is essentially a superset of other options and one of the things it does is limit resolution to VGA. It also didn't help until after a full apt upgrade.
I'm not sure why this happens with a new batch of Pi 4's and not with the old. I'm guessing firmware but realistically the only way is forward with that.
I've no idea how much work I'm asking here but would it be worth putting out a new build that just updates everything around FullPageOS? Essentially doing the apt update, apt upgrade in advance. The config.txt options could be preset but can be set directly in text files on the card. To do an upgrade over SSH with no screen output adds a hurdle that a lot of people are going to give the whole thing a miss.

[guysoft]

Sounds like an FAQ entry: https://github.com/guysoft/FullPageOS/wiki/FAQ
Added: https://github.com/guysoft/FullPageOS/wiki/FAQ#my-display-works-on-a-computer-screen-but-not-on-another-display
You are welcome to change it if you think it needs changes