# Display controls

Turn off the display and adjust screen brightness.

---

## Turn display on or off

1. ### Verify framebuffer support

   The framebuffer blanking control may not be available or supported by every graphics driver.

   ```sh
   ls /sys/class/backlight/
   ```

2. ### Turn display off

   ```sh
   echo 1 | sudo tee /sys/class/graphics/fb0/blank
   ```

3. ### Turn display on

   ```sh
   echo 0 | sudo tee /sys/class/graphics/fb0/blank
   ```

---

## Adjust display brightness

1. ### Identify backlight controllers

   ```sh
   ls /sys/class/backlight/
   ```

2. ### Set minimum brightness

   ```sh
   echo 0 | sudo tee /sys/class/backlight/acpi_video0/brightness; echo 0 | sudo tee /sys/class/backlight/acpi_video1/brightness
   ```

3. ### Check maximum brightness

   ```sh
   cat /sys/class/backlight/acpi_video0/max_brightness; cat /sys/class/backlight/acpi_video1/max_brightness
   ```

4. ### Set maximum brightness

   ```sh
   echo 84 | sudo tee /sys/class/backlight/acpi_video0/brightness; echo 84 | sudo tee /sys/class/backlight/acpi_video1/brightness
   ```