retropi disabled my pis hdmi

Katy

Pi Model or other hardware: Pi 4 (4GB)
Power Supply used: Original Pi 4 adapter
RetroPie Version Used: 4.6.4
Built From: on top of Raspian Buster (2020-05-27-raspios-buster-armhf.zip)
USB Devices connected: generic keyboard, mous, gamepad
Controller used: noname snes like
Error messages received: none
Verbose log (if relevant):

$ tvservice -l
2 attached device(s), display ID's are :
Display Number 0, type Main LCD
Display Number 2, type HDMI 0

Guide used: https://retropie.org.uk/docs/Manual-Installation/
Attachment of config files: /boot/config.txt

How to replicate the problem:

I have a pi4 with Raspberry Pi OS (=raspian) as desktop computer hooked up to a monitor via hdmi and to the official raspberry 7" touchdisplay on the DSI port. Decided to install retropi on to of it by the manual way, following the official guide: https://retropie.org.uk/docs/Manual-Installation/

It worked fine, but after the reboot, the hdmi output was disabled and I can't get it back on. Only the 7" display is used (but that works fine for desktop and emulationstation)

Some more info

Before the retropi installation, both hdmi monitor and 7" display worked with the mirrored image - this is what I need back.
The monitor still works fine with other devices
Booting, the hdmi monitor shows the berrys, then it goes black (but does not turn of, as it does without any signal)

This is what I tried so far:

The monitor is found and seems to receive a signal:

$ tvservice -l
2 attached device(s), display ID's are :
Display Number 0, type Main LCD
Display Number 2, type HDMI 0

In the /boot/config.txt

tried hdmi_safe=1 with no effect
tried config_hdmi_boost=4 with no effect
hdmi_group=2 / hdmi_mode=9 is working for the 7" screen
hdmi_group=1 / hdmi_mode=16 would be the correct one for the monitor (worked before)
did restarts after every change

Tried to change the primary display in raspians "screen configuration" tool, but could not find out if and how that would be supported.

After spending a while searching how to configure this, I decided to uninstall retropi. But the hdmi output is still not working! Next thing would be to start with a new image, if nobody has another idea for me... :(

So thanks for anny suggestions!

Cheers, K

mitu

@Katy said in retropi disabled my pis hdmi:

Tried to change the primary display in raspians "screen configuration" tool, but could not find out if and how that would be supported.

It's not - RetroPie doesn't use the desktop environment. More likely the mirroring you had in place was done in the desktop environment, if you disabled it - as it's recommended by the installation doc - then the mirroring will not take place.

Katy

@mitu thanks for the input!
I don't find the part disabeling the desktop environment in the installation doc I followed, could you pease specify which doc you refer to?
I don't think I disabled the desktop (and did not mean to), because the pi boots into the desktop environment as I want it to (because I need to use it) - just not getting video out over hdmi.

mitu

@Katy said in retropi disabled my pis hdmi:

I don't find the part disabeling the desktop environment in the installation doc I followed, could you pease specify which doc you refer to?

From the doc page:

The RetroPie SD image is built on top of Raspbian lite (Raspbian without the PIXEL desktop environment) RetroPie can also be installed on top of the full Raspbian but you can't run Retropie and PIXEL at the same time, you will need to logout of the PIXEL desktop environment in order to run emulationstation and the emulators RetroPie installs.

I don't think I disabled the desktop (and did not mean to), because the pi boots into the desktop environment as I want it to (because I need to use it) - just not getting video out over hdmi.

In this case, I don't know what can cause this, but RetroPie doesn't modify your existing desktop settings or the video settings (those in /boot/config.txt).

Katy

Thanks again.

I found how to fix it, in case anyone stumbles upon the same problem:

xset -display :0 dpms force on

enabled my hdmi monitor again.

Going to reinstall retropi again, see if it breaks again and if I can fix it like this again.