LinuxQuestions.org

LinuxQuestions.org (/questions/)
-   Slackware - ARM (https://www.linuxquestions.org/questions/slackware-arm-108/)
-   -   SARPI (fatdog) on RPi4 - no HDMI video [SOLVED] (https://www.linuxquestions.org/questions/slackware-arm-108/sarpi-fatdog-on-rpi4-no-hdmi-video-%5Bsolved%5D-4175668198/)

arfon 01-22-2020 07:14 AM
SARPI (fatdog) on RPi4 - no HDMI video [SOLVED]
 
When I booted the RPi4 from the newly "xc"'d sdcard there was no HDMI video. The fix was to uncomment the following two lines in config.txt (in the mmcblk0p1 partition):

Code:
# Uncomment if you get no picture on HDMI for a default "safe" mode
hdmi_safe=1

# Uncomment if hdmi display is not detected and composite is being output
hdmi_force_hotplug=1

After installing SARPI and rebooting, again, no HDMI video... Again, the fix was to uncomment the same two lines in /boot/config.txt

Exaga 01-22-2020 03:38 PM
Quote:
Originally Posted by arfon (Post 6081522)
When I booted the RPi4 from the newly "xc"'d sdcard there was no HDMI video. The fix was to uncomment the following two lines in config.txt (in the mmcblk0p1 partition):

Code:
# Uncomment if you get no picture on HDMI for a default "safe" mode
hdmi_safe=1

# Uncomment if hdmi display is not detected and composite is being output
hdmi_force_hotplug=1

After installing SARPI and rebooting, again, no HDMI video... Again, the fix was to uncomment the same two lines in /boot/config.txt
OK cool. Thanks for this. I will certainly bear it in mind and if any other Slackers have the same experience as you then it'll become an issue to address. I've not had any problems of the kind you've described with Slackware ARM current on the RPi4. In fact, much the opposite.

TheTKS 01-22-2020 09:59 PM
Quote:
Originally Posted by Exaga (Post 6081719)
OK cool. Thanks for this. I will certainly bear it in mind and if any other Slackers have the same experience as you then it'll become an issue to address. I've not had any problems of the kind you've described with Slackware ARM current on the RPi4. In fact, much the opposite.
No problems here with HDMI video. Haven’t tried audio.

arfon 03-16-2020 02:17 AM
No HDMI output on RPi4 (why and fix)
 
I found out WHY the HDMI video doesn't work on some installs....

If you use an OLD monitor (or a TV) for the install, they may not be able to handle the high default resolution of the RPi4. When this is the case, the monitor just shows a black or a "no input signal" screen.

You can fix this by changing monitors -OR- changing the config file as I described in the first post.

Exaga 03-17-2020 01:47 AM
Quote:
Originally Posted by arfon (Post 6101041)
I found out WHY the HDMI video doesn't work on some installs....

If you use an OLD monitor (or a TV) for the install, they may not be able to handle the high default resolution of the RPi4. When this is the case, the monitor just shows a black or a "no input signal" screen.

You can fix this by changing monitors -OR- changing the config file as I described in the first post.
Sure thing. This happens when the video mode of the screen display cannot match the video mode that the RPi is using. It's a known quantity and can usually be fixed by altering one's /boot/config.txt settings to operate on a lower/lesser level. Part of the fun in getting things to work in Slackware ARM is solving issues such as these. Although, this is not a Slackware ARM [or SARPi] issue. It's all down to the capabilities of the screen display that you're using.

I generally try to connect via ssh when there's no expected display, and if that is working OK I then look at the video mode(s), then cables, etc. ;)


All times are GMT -5. The time now is 08:51 PM.