# Troubleshooting

This page will have common problems and common solutions to those problems.

## First Steps

The first step to troubleshooting any problem is getting the cause of the error.
Check for the file `/tmp/KlipperScreen.log` and look at the contents by running
`cat /tmp/KlipperScreen.log` or grab the file over WinSCP or another sftp program.

If that file is non-existent, run `journalctl -xe -u KlipperScreen` and check `/var/log/Xorg.0.log`
where you can find issues with the X server.


## Common Errors

### Problems occurring before the log file appears

This section will detail problems that may happen before the log file has been created. Each section will start with a
relevant line from the journalctl output.

#### Cannot open virtual Console
```
xf86OpenConsole: Cannot open virtual console 2 (Permission denied)
```

* Check /etc/X11/Xwrapper.conf
This should have the line `allowed_users=anybody` in it
* Check /etc/group
Run the command `cat /etc/group | grep tty`. If your username is not listed under that line, you need to add it with the
following command (if your username is not 'pi' change 'pi' to your username):
`usermod -a -G tty pi`


### Problems occurring with the log file

#### Screen shows console instead of KlipperScreen
Run the command `ls /dev/fb*`. If you have multiple devices, you may need to fix the X11 configuration.

Run the command `cat /usr/share/X11/xorg.conf.d/99-fbturbo.conf | grep /dev/fb`. Try modifying the file (
`sudo nano /usr/share/X11/xorg.conf.d/99-fbturbo.conf`) and change `/dev/fb0` to a different file listed in the
previous command (i.e. `/dev/fb1`).

Once you have saved that file, restart KlipperScreen and it should show up on your display.

#### Screen is all white or blank

Improperly installed screen, follow the manufacturer instructions on how to physically connect the screen and install
the proper drivers.

### Touch not working on debian Bullseye

Some dsi screens have issues where touch doesn't work with debian bullseye, the current fix
(at least until upstream is fixed) consist in runnig `raspi-config`> go to Advanced > GL Driver
select G2 and reboot.

![config](img/troubleshooting/gldriver.png)

Or manually edit `/boot/config.txt` and change:

`dtoverlay=vc4-kms-v3d`

to:

`dtoverlay=vc4-fkms-v3d`

and reboot, that should make the touch work, if your screen is rotated 180 degrees, then you may need to adjust
[the touch rotation](Hardware.md) as described in the Hardware page.