TX2-4GB HDMI connection display problem

Robotics & Edge Computing Jetson & Embedded Systems Jetson TX2
,
1

The l4t version is updated, 32.3.1 is updated to 32.5. The HDMI is not connected during startup, and the HDMI cable is connected after startup, the GUI interface cannot be displayed. The previous version has no problem, but the new version has this problem.
Plug in HDMI to start up and display the desktop normally . What is the reason for this? In addition, the previous version is the Ubuntu desktop, after the update is the LXDE desktop.
Switch to the command line interface:

pca953x 0-0074: failed reading register
pca953x 0-0077: failed reading register
tegradc 15210000.nvdisplay:dc_hdmi_hotplug_init:couldn't get regulator vdd_hdmi_5v0, -517
FAN:couldn't get the regulator
3

Are you using custom carrier board?

What is your method to update from rel32.3 to 32.5.1?

4

Yes.
First use SDKManager to download JetPack4.5, modify the USB and emmc of the device tree in the l4t-32.5 source package to adapt to our custom carrier board, and then use the programming command:
sudo ./flash.sh jetson-tx2-4GB mmcblk0p1

5

And did you modify something for hdmi to make it work?

6

No, I don’t know how to modify it.
Is this related to the upgraded version?

7

There are two different issues here.

  1. Every peripheral may need to modify device tree when it is custom board. I think that error was on rel-32.3.1 too but you just didn’t notice it. Please share the full dmesg now so that we can know what happens to HDMI.

  2. For device with <=4GB RAM, the default display manager is lightdm. And by default lightdm is using LXDE.
    This is added after we published jetson nano 2gb.

the previous version is the Ubuntu desktop, after the update is the LXDE desktop.

You can check /etc/systemd/nvfb-early.sh to see this change.

8

HDMI is connected after startup, no display:
nodisplay_dmesy.log (58.8 KB)
Connect the HDMI cable before starting, the normal display:
normal_dmesg.log (58.5 KB)

Please help me analyze it, thank you

Can jetpack4.5 modify the default display manager to use the Ubuntu desktop? If it can be modified, what should I do?

9

Please check what is inside this file on your device

/etc/X11/default-display-manager

10 
/usr/sbin/lightdm
11

please change it to /usr/sbin/gdm3 and reboot to see if it is back to original desktop now.

12

No, restarting cannot enter the desktop normally, but entering the terminal.

13

So the screen can show the terminal?

14

Yes. Some failure messages flashed on the startup interface, and then entered the terminal.
(The HDMI cable is always connected)

15

Please try with command and reboot.

sudo dpkg-reconfigure gdm3

HDMI driver has no issue there since the terminal is able to show up. Only problem is ubuntu desktop.

16

Great, solved, thanks WayneWWW!

18

This topic was automatically closed 60 days after the last reply. New replies are no longer allowed.