You can follow the steps below to turn off the key beep:
(1) Enter the main menu, and go to the service menu with the password “9999”, as shown in the following screenshots.
Figure 2-24 Menu and Service Menu
(2) choose “④Function Setting” and press enter. You will see the following.
Figure 2-25 Function Setting Interface
(3) Press the key beep to toggle this setting.
Figure 2-26 Menu and Service Menu