Coco l'asticot
Posts: 4
Joined: Mon Dec 02, 2019 12:40 pm

No X display (black screen) after boot.

Mon Dec 02, 2019 1:21 pm

I have a Rapsberry Pi model B rev 2.0, with Raspbian GNU/Linux 10 (buster), running Linux 4.19.85+.
I put a LCD 7" touchscreen on it, and the display is working (after having done the trick explained here). At least in text mode.

The whole is powered with two USB cables plugged on my workstation USB ports (so, with a good power supply I think). One cable is plugged on the rpi's micro-usb port, and the other on the display's port. If I don't plug the rpi's micro-usb port, there isn't enough current to active the Wifi dongle.

I manage to login through the tty console using the display and a connected keyboard, or via ssh from my workstation.

I have LXDE with lightdm installed, but I can't get the graphics using startx, nor using lightdm. Nothing appears, the screen turns black and I lose the keyboard control (I can't switch to tty2, tty3 etc.) The only way then is to reboot from ssh.
I have tried other things: xinit openbox, xinit startlxde-pi, startx, sudo systemctl start slim, etc.

The Xorg log doesn't seem to contain any errors:

Code: Select all

X.Org X Server 1.20.4
X Protocol Version 11, Revision 0
[   655.059] Build Operating System: Linux 4.15.0-48-generic armv8l Raspbian
[   655.059] Current Operating System: Linux pave 4.19.85+ #1279 Fri Nov 22 15:30:38 GMT 2019 armv6l
[   655.059] Kernel command line: coherent_pool=1M bcm2708_fb.fbwidth=800 bcm2708_fb.fbheight=480 bcm2708_fb.fbswap=1 vc_mem.mem_base=0x1ec00000 vc_mem.mem_size=0x20000000  dwc_otg.lpm_enable=0 console=ttyAMA0,115200 console=tty1 root=PARTUUID=686ad6a5-02 rootfstype=ext4 elevator=deadline fsck.repair=yes rootwait
[   655.061] Build Date: 05 June 2019  12:49:54PM
[   655.061] xorg-server 2:1.20.4-1+rpt1 (https://www.debian.org/support) 
[   655.061] Current version of pixman: 0.36.0
[   655.061]    Before reporting problems, check http://wiki.x.org
        to make sure that you have the latest version.
[   655.062] Markers: (--) probed, (**) from config file, (==) default setting,
        (++) from command line, (!!) notice, (II) informational,
        (WW) warning, (EE) error, (NI) not implemented, (??) unknown.
[   655.063] (==) Log file: "/var/log/Xorg.0.log", Time: Mon Dec  2 12:59:11 2019
[   655.065] (==) Using system config directory "/usr/share/X11/xorg.conf.d"
[   655.068] (==) No Layout section.  Using the first Screen section.
[   655.069] (==) No screen section available. Using defaults.
[   655.069] (**) |-->Screen "Default Screen Section" (0)
[   655.069] (**) |   |-->Monitor "<default monitor>"
[   655.074] (==) No device specified for screen "Default Screen Section".
        Using the first device section listed.
[   655.075] (**) |   |-->Device "Allwinner A10/A13 FBDEV"
[   655.075] (==) No monitor specified for screen "Default Screen Section".
        Using a default monitor configuration.
[   655.075] (==) Automatically adding devices
[   655.075] (==) Automatically enabling devices
[   655.075] (==) Automatically adding GPU devices
[   655.076] (==) Max clients allowed: 256, resource mask: 0x1fffff
[   655.076] (WW) The directory "/usr/share/fonts/X11/cyrillic" does not exist.
[   655.076]    Entry deleted from font path.
[   655.077] (==) FontPath set to:
        /usr/share/fonts/X11/misc,
        /usr/share/fonts/X11/100dpi/:unscaled,
        /usr/share/fonts/X11/75dpi/:unscaled,
        /usr/share/fonts/X11/Type1,
        /usr/share/fonts/X11/100dpi,
        /usr/share/fonts/X11/75dpi,
        built-ins
[   655.077] (==) ModulePath set to "/usr/lib/xorg/modules"
[   655.077] (II) The server relies on udev to provide the list of input devices.
        If no devices become available, reconfigure udev or disable AutoAddDevices.
[   655.077] (II) Loader magic: 0x1fcf80
[   655.078] (II) Module ABI versions:
[   655.078]    X.Org ANSI C Emulation: 0.4
[   655.078]    X.Org Video Driver: 24.0
[   655.078]    X.Org XInput driver : 24.1
[   655.078]    X.Org Server Extension : 10.0
[   655.091] (++) using VT number 7

[   655.091] (II) systemd-logind: logind integration requires -keeptty and -keeptty was not provided, disabling logind integration
[   655.093] (II) no primary bus or device found
[   655.093] (II) LoadModule: "glx"
[   655.095] (II) Loading /usr/lib/xorg/modules/extensions/libglx.so
[   655.188] (II) Module glx: vendor="X.Org Foundation"
[   655.188]    compiled for 1.20.4, module version = 1.0.0
[   655.188]    ABI class: X.Org Server Extension, version 10.0
[   655.189] (II) LoadModule: "fbturbo"
[   655.190] (II) Loading /usr/lib/xorg/modules/drivers/fbturbo_drv.so
[   655.192] (II) Module fbturbo: vendor="X.Org Foundation"
[   655.192]    compiled for 1.20.3, module version = 0.5.1
[   655.192]    Module class: X.Org Video Driver
[   655.193]    ABI class: X.Org Video Driver, version 24.0
[   655.193] (II) FBTURBO: driver for framebuffer: fbturbo
[   655.194] (WW) Falling back to old probe method for fbturbo
[   655.194] (II) Loading sub module "fbdevhw"
[   655.194] (II) LoadModule: "fbdevhw"
[   655.196] (II) Loading /usr/lib/xorg/modules/libfbdevhw.so
[   655.198] (II) Module fbdevhw: vendor="X.Org Foundation"
[   655.198]    compiled for 1.20.4, module version = 0.0.2
[   655.198]    ABI class: X.Org Video Driver, version 24.0
[   655.199] (II) FBTURBO(0): using /dev/fb0
[   655.199] (WW) VGA arbiter: cannot open kernel arbiter, no multi-card support
[   655.200] (II) FBTURBO(0): Creating default Display subsection in Screen section
        "Default Screen Section" for depth/fbbpp 24/32
[   655.201] (==) FBTURBO(0): Depth 24, (==) framebuffer bpp 32
[   655.201] (==) FBTURBO(0): RGB weight 888
[   655.201] (==) FBTURBO(0): Default visual is TrueColor
[   655.201] (==) FBTURBO(0): Using gamma correction (1.0, 1.0, 1.0)
[   655.202] (II) FBTURBO(0): hardware: BCM2708 FB (video memory: 1500kB)
[   655.202] (DB) xf86MergeOutputClassOptions unsupported bus type 0
[   655.202] (**) FBTURBO(0): Option "fbdev" "/dev/fb0"
[   655.203] (**) FBTURBO(0): Option "SwapbuffersWait" "true"
[   655.204] (II) FBTURBO(0): processor: ARM1176
[   655.204] (II) FBTURBO(0): checking modes against framebuffer device...
[   655.205] (II) FBTURBO(0): checking modes against monitor...
[   655.205] (II) FBTURBO(0): Virtual size is 800x480 (pitch 800)
[   655.205] (**) FBTURBO(0):  Built-in mode "current"
[   655.206] (==) FBTURBO(0): DPI set to (96, 96)
[   655.206] (II) Loading sub module "fb"
[   655.206] (II) LoadModule: "fb"
[   655.208] (II) Loading /usr/lib/xorg/modules/libfb.so
[   655.209] (II) Module fb: vendor="X.Org Foundation"
[   655.210]    compiled for 1.20.4, module version = 1.0.0
[   655.210]    ABI class: X.Org ANSI C Emulation, version 0.4
[   655.213] (II) FBTURBO(0): using backing store heuristics
[   655.266] (II) FBTURBO(0): can't load 'g2d_23' kernel module
[   655.266] (II) FBTURBO(0): failed to enable the use of sunxi display controller
[   655.267] (II) FBTURBO(0): No sunxi-g2d hardware detected (check /dev/disp and /dev/g2d)
[   655.267] (II) FBTURBO(0): G2D hardware acceleration can't be enabled
[   655.267] (II) FBTURBO(0): enabled fbdev copyarea acceleration
[   655.268] (==) FBTURBO(0): Backing store enabled
[   655.270] (==) FBTURBO(0): DPMS enabled
[   655.271] (II) FBTURBO(0): failed to enable hardware cursor
[   655.271] (II) FBTURBO(0): no 3D acceleration because the driver has been compiled without libUMP
[   655.271] (II) FBTURBO(0): if this is wrong and needs to be fixed, please check ./configure log
[   655.272] (II) Initializing extension Generic Event Extension
[   655.275] (II) Initializing extension SHAPE
[   655.277] (II) Initializing extension MIT-SHM
[   655.280] (II) Initializing extension XInputExtension
[   655.284] (II) Initializing extension XTEST
[   655.286] (II) Initializing extension BIG-REQUESTS
[   655.289] (II) Initializing extension SYNC
[   655.292] (II) Initializing extension XKEYBOARD
[   655.295] (II) Initializing extension XC-MISC
[   655.298] (II) Initializing extension SECURITY
[   655.301] (II) Initializing extension XFIXES
[   655.304] (II) Initializing extension RENDER
[   655.307] (II) Initializing extension RANDR
[   655.313] (II) Initializing extension COMPOSITE
[   655.316] (II) Initializing extension DAMAGE
[   655.318] (II) Initializing extension MIT-SCREEN-SAVER
[   655.321] (II) Initializing extension DOUBLE-BUFFER
[   655.324] (II) Initializing extension RECORD
[   655.327] (II) Initializing extension DPMS
[   655.329] (II) Initializing extension Present
[   655.332] (II) Initializing extension DRI3
[   655.332] (II) Initializing extension X-Resource
[   655.335] (II) Initializing extension XVideo
[   655.338] (II) Initializing extension XVideo-MotionCompensation
[   655.338] (II) Initializing extension SELinux
[   655.338] (II) SELinux: Disabled on system
[   655.338] (II) Initializing extension GLX
[   655.341] (II) AIGLX: Screen 0 is not DRI2 capable
[   656.214] (II) IGLX: Loaded and initialized swrast
[   656.220] (II) GLX: Initialized DRISWRAST GL provider for screen 0
[   656.220] (II) Initializing extension XFree86-VidModeExtension
[   656.223] (II) Initializing extension XFree86-DGA
[   656.226] (II) Initializing extension XFree86-DRI
[   656.226] (II) Initializing extension DRI2
[   657.014] (II) config/udev: Adding input device FT5406 memory based driver (/dev/input/event0)
[   657.015] (**) FT5406 memory based driver: Applying InputClass "libinput touchscreen catchall"
[   657.016] (**) FT5406 memory based driver: Applying InputClass "tslib touchscreen"
[   657.016] (II) LoadModule: "tslib"
[   657.017] (II) Loading /usr/lib/xorg/modules/input/tslib_drv.so
[   657.021] (II) Module tslib: vendor="X.Org Foundation"
[   657.021]    compiled for 1.20.3, module version = 0.0.1
[   657.021]    Module class: X.Org XInput Driver
[   657.021]    ABI class: X.Org XInput driver, version 24.1
[   657.022] (II) Using input driver 'tslib' for 'FT5406 memory based driver'
[   657.022] (**) FT5406 memory based driver: always reports core events
[   657.022] (**) FT5406 memory based driver: always reports core events
[   657.029] (**) Option "config_info" "udev:/sys/devices/virtual/input/input0/event0"
[   657.030] (II) XINPUT: Adding extended input device "FT5406 memory based driver" (type: TOUCHSCREEN, id 6)
[   657.030] xf86TslibControlProc
[   657.031] (**) FT5406 memory based driver: (accel) keeping acceleration scheme 1
[   657.031] (**) FT5406 memory based driver: (accel) acceleration profile 0
[   657.031] (**) FT5406 memory based driver: (accel) acceleration factor: 2.000
[   657.032] (**) FT5406 memory based driver: (accel) acceleration threshold: 4
[   657.032] xf86TslibControlProc
Here are the logs from lightdm (I didn't modify its conf file):

Code: Select all

[+0.00s] DEBUG: Logging to /var/log/lightdm/lightdm.log
[+0.00s] DEBUG: Starting Light Display Manager 1.26.0, UID=0 PID=1214
[+0.00s] DEBUG: Loading configuration dirs from /usr/share/lightdm/lightdm.conf.d
[+0.00s] DEBUG: Loading configuration from /usr/share/lightdm/lightdm.conf.d/01_debian.conf
[+0.00s] DEBUG: Loading configuration dirs from /usr/local/share/lightdm/lightdm.conf.d
[+0.00s] DEBUG: Loading configuration dirs from /etc/xdg/lightdm/lightdm.conf.d
[+0.00s] DEBUG: Loading configuration from /etc/lightdm/lightdm.conf
[+0.00s] DEBUG: Registered seat module local
[+0.01s] DEBUG: Registered seat module xremote
[+0.01s] DEBUG: Registered seat module unity
[+0.01s] DEBUG: Using D-Bus name org.freedesktop.DisplayManager
[+0.10s] DEBUG: Monitoring logind for seats
[+0.10s] DEBUG: New seat added from logind: seat0
[+0.10s] DEBUG: Seat seat0: Loading properties from config section Seat:*
[+0.10s] DEBUG: Seat seat0: Starting
[+0.10s] DEBUG: Seat seat0: Creating user session
[+0.12s] DEBUG: Loading users from org.freedesktop.Accounts
[+0.12s] DEBUG: User /org/freedesktop/Accounts/User56244 added
[+0.19s] DEBUG: User /org/freedesktop/Accounts/User56243 added
[+0.29s] DEBUG: Seat seat0: Creating display server of type x
[+0.29s] DEBUG: posix_spawn avoided (fd close requested) 
[+0.31s] DEBUG: Using VT 7
[+0.31s] DEBUG: Seat seat0: Starting local X display on VT 7
[+0.32s] DEBUG: XServer 0: Logging to /var/log/lightdm/x-0.log
[+0.32s] DEBUG: XServer 0: Writing X server authority to /var/run/lightdm/root/:0
[+0.32s] DEBUG: XServer 0: Launching X Server
[+0.32s] DEBUG: Launching process 1221: /usr/bin/X :0 -seat seat0 -auth /var/run/lightdm/root/:0 -nolisten tcp vt7 -novtswitch
[+0.32s] DEBUG: XServer 0: Waiting for ready signal from X server :0
[+0.32s] DEBUG: Acquired bus name org.freedesktop.DisplayManager
[+0.33s] DEBUG: Registering seat with bus path /org/freedesktop/DisplayManager/Seat0
[+2.43s] DEBUG: Process 1221 exited with return value 127
[+2.43s] DEBUG: XServer 0: X server stopped
[+2.43s] DEBUG: Releasing VT 7
[+2.43s] DEBUG: XServer 0: Removing X server authority /var/run/lightdm/root/:0
[+2.43s] DEBUG: Seat seat0: Display server stopped
[+2.43s] DEBUG: Seat seat0: Stopping session
[+2.43s] DEBUG: Seat seat0: Session stopped
[+2.43s] DEBUG: Seat seat0: Stopping display server, no sessions require it
[+2.44s] DEBUG: Seat seat0: Active display server stopped, starting greeter
[+2.44s] DEBUG: Seat seat0: Creating greeter session
[+2.44s] DEBUG: Seat seat0: Creating display server of type x
[+2.44s] DEBUG: Using VT 7
[+2.44s] DEBUG: Seat seat0: Starting local X display on VT 7
[+2.44s] DEBUG: XServer 0: Logging to /var/log/lightdm/x-0.log
[+2.44s] DEBUG: XServer 0: Writing X server authority to /var/run/lightdm/root/:0
[+2.44s] DEBUG: XServer 0: Launching X Server
[+2.45s] DEBUG: Launching process 1234: /usr/bin/X :0 -seat seat0 -auth /var/run/lightdm/root/:0 -nolisten tcp vt7 -novtswitch
[+2.45s] DEBUG: XServer 0: Waiting for ready signal from X server :0
[+4.66s] DEBUG: Process 1234 exited with return value 127
[+4.66s] DEBUG: XServer 0: X server stopped
[+4.66s] DEBUG: Releasing VT 7
[+4.66s] DEBUG: XServer 0: Removing X server authority /var/run/lightdm/root/:0
[+4.67s] DEBUG: Seat seat0: Display server stopped
[+4.67s] DEBUG: Seat seat0: Stopping session
[+4.67s] DEBUG: Seat seat0: Session stopped
[+4.67s] DEBUG: Seat seat0: Stopping display server, no sessions require it
[+4.67s] DEBUG: Seat seat0: Stopping; greeter display server failed to start
[+4.67s] DEBUG: Seat seat0: Stopping
[+4.67s] DEBUG: Seat seat0: Stopped
[+4.67s] DEBUG: Required seat has stopped
[+4.67s] DEBUG: Stopping display manager
[+4.67s] DEBUG: Display manager stopped
[+4.67s] DEBUG: Stopping daemon
[+4.75s] DEBUG: Exiting with return value 1
No useful error messages in dmesg, journalctl or ~/.xsession-errors...

Any ideas?

2019-12-05 EDIT: I am using the official display!
Last edited by Coco l'asticot on Thu Dec 05, 2019 2:06 pm, edited 1 time in total.
A road that lets you go faster is not better if it leads to the wrong place.

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FTrevorGowen
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Re: No X display (black screen) after boot.

Mon Dec 02, 2019 3:17 pm

Coco l'asticot wrote:
Mon Dec 02, 2019 1:21 pm

...

The whole is powered with two USB cables plugged on my workstation USB ports (so, with a good power supply I think). One cable is plugged on the rpi's micro-usb port, and the other on the display's port. If I don't plug the rpi's micro-usb port, there isn't enough current to active the Wifi dongle.

...

Any ideas?
I suspect not "a good power supply" - you may find these, now somewhat old, tests of hub loading behaviour of interest:
https://www.cpmspectrepi.uk/raspberry_p ... BHubs.html
There's no guarantee that a device having more than one USB port can supply N x 1 port's current limit from N ports. To put it another way a Pi is not the only multi-USB port device where the 5V "output" connection is common to all ports - one of the historical causes of 'Y' cabled USB drive caddies not always working as well as might be expected.
Trev.
Still running Raspbian Jessie or Stretch on some older Pi's (an A, B1, B2, B+, P2B, 3xP0, P0W, 2xP3A+, P3B+, P3B, B+, A+ and a B2) but Buster on the P4B's. See: https://www.cpmspectrepi.uk/raspberry_pi/raspiidx.htm

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procount
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Location: UK

Re: No X display (black screen) after boot.

Mon Dec 02, 2019 3:21 pm

Have you expanded the file system?
Lack of free disk space causes the desktop to fail in odd ways.
PINN - NOOBS with the extras... https://www.raspberrypi.org/forums/viewtopic.php?f=63&t=142574

Coco l'asticot
Posts: 4
Joined: Mon Dec 02, 2019 12:40 pm

Re: No X display (black screen) after boot.

Tue Dec 03, 2019 2:41 pm

There's no guarantee that a device having more than one USB port can supply N x 1 port's current limit from N ports.
I didn't know that, thank you.
I am now testing it with a 5.2V x 2.4A alimentation adapter, the Wifi dongle and the screen are activated, but no more X display.

About the lack of free space, I did extend the filesystem using raspi-config, and now df -h returns:

Code: Select all

/dev/root           15G    4,5G  9,5G  33% /
devtmpfs           181M       0  181M   0% /dev
tmpfs              185M       0  185M   0% /dev/shm
tmpfs              185M    3,1M  182M   2% /run
tmpfs              5,0M    4,0K  5,0M   1% /run/lock
tmpfs              185M       0  185M   0% /sys/fs/cgroup
/dev/mmcblk0p1      44M     23M   21M  53% /boot
tmpfs               37M       0   37M   0% /run/user/56243
So, any other ideas? :?
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FTrevorGowen
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Re: No X display (black screen) after boot.

Tue Dec 03, 2019 3:48 pm

Coco l'asticot wrote:
Tue Dec 03, 2019 2:41 pm
There's no guarantee that a device having more than one USB port can supply N x 1 port's current limit from N ports.
I didn't know that, thank you.
I am now testing it with a 5.2V x 2.4A alimentation adapter, the Wifi dongle and the screen are activated, but no more X display.

About the lack of free space, I did extend the filesystem using raspi-config, and now df -h returns:

Code: Select all

/dev/root           15G    4,5G  9,5G  33% /
devtmpfs           181M       0  181M   0% /dev
tmpfs              185M       0  185M   0% /dev/shm
tmpfs              185M    3,1M  182M   2% /run
tmpfs              5,0M    4,0K  5,0M   1% /run/lock
tmpfs              185M       0  185M   0% /sys/fs/cgroup
/dev/mmcblk0p1      44M     23M   21M  53% /boot
tmpfs               37M       0   37M   0% /run/user/56243
So, any other ideas? :?
O.K. In your O.P. you did mention you can connect via SSH etc. Can you post the output of these tvservice commands please?

Code: Select all

tvservice -n
tvservice -m DMT
tvservice -m CEA
tvservice -s
Also, what changes, if any, have you made to /boot/config.txt? (eg. have you un-commented, by deleting the leading '#' character, any HDMI-associated lines)
Trev.
Still running Raspbian Jessie or Stretch on some older Pi's (an A, B1, B2, B+, P2B, 3xP0, P0W, 2xP3A+, P3B+, P3B, B+, A+ and a B2) but Buster on the P4B's. See: https://www.cpmspectrepi.uk/raspberry_pi/raspiidx.htm

Coco l'asticot
Posts: 4
Joined: Mon Dec 02, 2019 12:40 pm

Re: No X display (black screen) after boot.

Wed Dec 04, 2019 10:25 pm

FTrevorGowen wrote:
Tue Dec 03, 2019 3:48 pm
O.K. In your O.P. you did mention you can connect via SSH etc. Can you post the output of these tvservice commands please?
Here there are:

Code: Select all

$ tvservice -n
device_name=Ras-LCD Panel
$ tvservice -m DMT
Group DMT has 0 modes:
$ tvservice -m CEA
Group CEA has 0 modes:
$ tvservice -s
state 0x400000 [LCD], 800x480 @ 60.00Hz, progressive
FTrevorGowen wrote:
Tue Dec 03, 2019 3:48 pm
Also, what changes, if any, have you made to /boot/config.txt? (eg. have you un-commented, by deleting the leading '#' character, any HDMI-associated lines)
The only two modified lines in this file are:

Code: Select all

ignore_lcd=0
and

Code: Select all

dtparam=audio=on
All other parameters (including HDMI) are kept to their default values.
A road that lets you go faster is not better if it leads to the wrong place.

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FTrevorGowen
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Re: No X display (black screen) after boot.

Wed Dec 04, 2019 11:07 pm

Coco l'asticot wrote:
FTrevorGowen wrote:
Tue Dec 03, 2019 3:48 pm
O.K. In your O.P. you did mention you can connect via SSH etc. Can you post the output of these tvservice commands please?
Here there are:

Code: Select all

$ tvservice -n
device_name=Ras-LCD Panel
$ tvservice -m DMT
Group DMT has 0 modes:
$ tvservice -m CEA
Group CEA has 0 modes:
$ tvservice -s
state 0x400000 [LCD], 800x480 @ 60.00Hz, progressive
FTrevorGowen wrote:
Tue Dec 03, 2019 3:48 pm
Also, what changes, if any, have you made to /boot/config.txt? (eg. have you un-commented, by deleting the leading '#' character, any HDMI-associated lines)
The only two modified lines in this file are:

Code: Select all

ignore_lcd=0
and

Code: Select all

dtparam=audio=on
All other parameters (including HDMI) are kept to their default values.
Sorry, I'd forgot you were using an LCD display (not using HDMI). In that situation the tvservice command is not that helpful as can be seen even when used with the official display**:

Code: Select all

pi@raspi3Aplus2:~ $ tvservice -n
[E] No device present
pi@raspi3Aplus2:~ $ tvservice -m DMT
Group DMT has 0 modes:
pi@raspi3Aplus2:~ $ tvservice -m CEA
Group CEA has 0 modes:
pi@raspi3Aplus2:~ $ tvservice -s
state 0x400000 [LCD], 800x480 @ 60.00Hz, progressive
Trev.
** https://www.cpmspectrepi.uk/raspberry_p ... splay.html
Still running Raspbian Jessie or Stretch on some older Pi's (an A, B1, B2, B+, P2B, 3xP0, P0W, 2xP3A+, P3B+, P3B, B+, A+ and a B2) but Buster on the P4B's. See: https://www.cpmspectrepi.uk/raspberry_pi/raspiidx.htm

Coco l'asticot
Posts: 4
Joined: Mon Dec 02, 2019 12:40 pm

Re: No X display (black screen) after boot.

Thu Dec 05, 2019 2:04 pm

FTrevorGowen wrote:
Wed Dec 04, 2019 11:07 pm
Sorry, I'd forgot you were using an LCD display (not using HDMI). In that situation the tvservice command is not that helpful as can be seen even when used with the official display**:
I don't understand…
I am using the official display (or at least a very similar model looking exactly the same as on your photos), and it doesn't plug on the HDMI port.
I connect it via the provided flexi-cable to my Raspberry display port as explained here, so I don't get why tvservice would return to me "[E] No device present"???
Isn't it better my LCD display being correctly recognized?
A road that lets you go faster is not better if it leads to the wrong place.

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Re: No X display (black screen) after boot.

Thu Dec 05, 2019 2:51 pm

Coco l'asticot wrote:
Thu Dec 05, 2019 2:04 pm
FTrevorGowen wrote:
Wed Dec 04, 2019 11:07 pm
Sorry, I'd forgot you were using an LCD display (not using HDMI). In that situation the tvservice command is not that helpful as can be seen even when used with the official display**:
I don't understand…
I am using the official display (or at least a very similar model looking exactly the same as on your photos), and it doesn't plug on the HDMI port.
I connect it via the provided flexi-cable to my Raspberry display port as explained here, so I don't get why tvservice would return to me "[E] No device present"???
Isn't it better my LCD display being correctly recognized?
Unfortunately the thread you linked to is quite old (>4years) and may be "out-of-date". Certainly I didn't need to modify the ribbon cable for mine and I followed the RPF's own instructions**. (I suspect that thread referred to an older version of the driver board - can't tell from your 'photo. whether it's the same as mine).
Trev.
** https://www.raspberrypi.org/documentati ... /README.md
Still running Raspbian Jessie or Stretch on some older Pi's (an A, B1, B2, B+, P2B, 3xP0, P0W, 2xP3A+, P3B+, P3B, B+, A+ and a B2) but Buster on the P4B's. See: https://www.cpmspectrepi.uk/raspberry_pi/raspiidx.htm

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