I started a thread about this in the 'beginner' forum, but it got a bit unwieldy as I stumbled through partial fixes, so let me summarize briefly:
1. I got a 3B+, hooked it up over HDMI, and everything was fine; I saw the desktop.
2. I switched from HDMI to 3.5mm->RCA (and rebooted), and got the rainbow screen, then 10 seconds of black screen, 1 second of raspberry logo, then nothing but black screen. I could SSH in successfully, but nothing would appear on the screen, not even after `export DISPLAY=:0`. It was clearly still outputting a signal though; my TV wouldn't return to static until I told the pi to shut down (over ssh). I tried plugging in a keyboard and typing some commands but it didn't seem to do anything.
3. I found this thread and changed `dtoverlay=vc4-kms-v3d,composite` to `dtoverlay=vc4-fkms-v3d,composite` (`kms` to `fkms`) in my config.txt, and that seemed to not help much at first -- but NOW, as soon as I plug in a USB keyboard, the black screen ends and I can see my desktop! Unplugging the keyboard again leaves the desktop visible, and I can launch things over SSH just fine.
What would be halting the startup process until a keyboard is connected? (I don't even press any keys on the keyboard; just connecting it is enough.) I'm assuming this isn't some intentional feature, because it didn't happen when I connected it over HDMI.
1. I got a 3B+, hooked it up over HDMI, and everything was fine; I saw the desktop.
2. I switched from HDMI to 3.5mm->RCA (and rebooted), and got the rainbow screen, then 10 seconds of black screen, 1 second of raspberry logo, then nothing but black screen. I could SSH in successfully, but nothing would appear on the screen, not even after `export DISPLAY=:0`. It was clearly still outputting a signal though; my TV wouldn't return to static until I told the pi to shut down (over ssh). I tried plugging in a keyboard and typing some commands but it didn't seem to do anything.
3. I found this thread and changed `dtoverlay=vc4-kms-v3d,composite` to `dtoverlay=vc4-fkms-v3d,composite` (`kms` to `fkms`) in my config.txt, and that seemed to not help much at first -- but NOW, as soon as I plug in a USB keyboard, the black screen ends and I can see my desktop! Unplugging the keyboard again leaves the desktop visible, and I can launch things over SSH just fine.
What would be halting the startup process until a keyboard is connected? (I don't even press any keys on the keyboard; just connecting it is enough.) I'm assuming this isn't some intentional feature, because it didn't happen when I connected it over HDMI.
Statistics: Posted by RavenWorks — Tue Jul 08, 2025 11:22 am