Strange vertical bands once libretro runs

Dolland

Hi!
I'm running a Pi Zero 2W with a 2A boost converter set at 5.2V, video output on composite, audio on PWM.

I have a really strange problem: when i startup the system, screen looks great, but once i run whatever libretro app like retroarch setting or whatever emulator (psx, ppsspp, gba), a set of vertical bands appear on the screen; these bands keep showing also on emulationstation and don't disappears even after emulationstation restart.
I have to reboot system to get rid of them.
Here are two pics on before and after bands appear.

Before: no banding
no bands.jpg

After: banding

I run a OSD but it doesn't seem to be the culprit, because bandings keep going also if i disable OSD.

What can the problem be?

EDIT:
I've understood that the problem arises as soon as i run any terminal applicative, like audio config, raspi-config or any other apps like that...

Dolland

No one has this problem?

windg

Do you have the same issue with the default carbon theme ? Try please to provide as much info you can https://retropie.org.uk/forum/topic/3/read-this-first

Dolland

@windg yes, it happens also with default carbon theme.
For further infos I'm using last stock retropie build, 4.8, no mods outside of an osd that runs also at system startup, when the bands doesn't appear and so I don't think is a osd problem also because when bands appear, disabling the osd doesn't make them disappear :⁠-⁠\

sirhenrythe5th

@Dolland just brainstorming: what happens when you disable this OSD at all, so it does not start up?

barbudreadmon

@Dolland hmmm, the thing that comes to mind is that it's not switching back to the same video mode after returning from an application ?
Maybe it'd help if you used another mode in pi's config.txt ?

Dolland

@sirhenrythe5th Will definitely check once I'll get my PC so i can ssh inside the pi.

@barbudreadmon
Uhm... in my config.txt (that i will post once i get a PC) i set PAL mode when using composite out, so may it be that once i start an app, sdtv mode changes and doesn't return back to the correct mode?
May it be that switching to NTSC comes with these bands?

And if that, how can it force the whole system to use the config.txt settings?

barbudreadmon

@Dolland sorry, i'm not familiar with those kind of setups so i won't be of much help, but i believe it's worth investigating.

mitu

@Dolland said in Strange vertical bands once libretro runs:

I've understood that the problem arises as soon as i run any terminal applicative, like audio config, raspi-config or any other apps like that...

Are you running EmulationStation from the desktop ?

Dolland

@mitu no, i'm not running emulationstation from desktop, it starts automatically at startup

@sirhenrythe5th also with the OSD service disabled, the behavior is the same :/

@barbudreadmon i checked the config.txt i'm running and i don't see any strange stuffs:

# For more options and information see
# http://rpf.io/configtxt
# Some settings may impact device functionality. See link above for details

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

# uncomment this if your display has a black border of unused pixels visible
# and your display can output without overscan
disable_overscan=0

# uncomment the following to adjust overscan. Use positive numbers if console
# goes off screen, and negative if there is too much border
overscan_left=0
overscan_right=-18
overscan_top=-10
overscan_bottom=-16

# uncomment to force a console size. By default it will be display's size minus
# overscan.
#framebuffer_width=1280
#framebuffer_height=720

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

# uncomment to force a specific HDMI mode (this will force VGA)
#hdmi_group=2
#hdmi_mode=23

# uncomment to force a HDMI mode rather than DVI. This can make audio work in
# DMT (computer monitor) modes
#hdmi_drive=2
# uncomment to increase signal to HDMI, if you have interference, blanking, or
# no display
#config_hdmi_boost=4

# uncomment for composite PAL
sdtv_mode=2
sdtv_aspect=3
#display_rotate=2
#uncomment to overclock the arm. 700 MHz is the default.
#arm_freq=800

# Uncomment some or all of these to enable the optional hardware interfaces
#dtparam=i2c_arm=off
#dtparam=i2s=on
#dtparam=spi=on

# Uncomment this to enable infrared communication.
#dtoverlay=gpio-ir,gpio_pin=17
#dtoverlay=gpio-ir-tx,gpio_pin=18

# Additional overlays and parameters are documented /boot/overlays/README

# Enable audio (loads snd_bcm2835)
dtparam=audio=on
#dtparam=audio=off
#dtoverlay=hifiberry-dac 
#dtoverlay=i2s-mmap
#dtoverlay=max98357a,no-sdmode
[pi4]
# Enable DRM VC4 V3D driver on top of the dispmanx display stack
dtoverlay=vc4-fkms-v3d
max_framebuffers=2

[all]
#dtoverlay=vc4-fkms-v3d
gpu_mem_256=128
gpu_mem_512=256
gpu_mem_1024=256
overscan_scale=1

#force_turbo=1

dtoverlay=pwm-2chan,pin=18,func=2,pin2=13,func2=4
dtoverlay=audremap,pin_13,enable_jack=on
disable_audio_dither=1
# this is config COMPOSITE
dtparam=i2c1=on

barbudreadmon

@Dolland Maybe https://discourse.osmc.tv/t/composite-output-in-raspberry-pi-fix/95697 would help ? They make some mention about dtoverlay stuff in config.txt and video resolution stuff in cmdline.txt

This is european PAL, right ? Apparently brazilian PAL might require 3 for sdtv_mode

Dolland

@barbudreadmon will try reading it, but thing is i don't have any problem untill i run something outside of emulationstation...
when system boots (and boot use config.ini settings) all is as it should be.

EDIT: i didn't find anything useful in that link :/