Samsung LS23B370HS-ZM - Manual (Page 48)

Using the product 3-15
3-15 Configuring Brightness and Contrast in the Initial Screen
Adjust the Brightness or Contrast setting using the [ ] buttons in the initial screen (where no OSD menu is displayed).
1. Press any button on the front of the product (when no menu screen is displayed) to display the Key guide. Next, press [ ].
The following screen will appear.
2. Press the [ ] button to alternate between the Brightness and Contrast settings.
3. Adjust the Brightness or Contrast setting using the [ ] buttons.