The way I was taught to test the phone, was to press intercom, then *00. This puts any phone in "test" mode. When you press each of the function buttons on the top panel of the 20L - it should display the button function. When you want to check the programmable buttons, touch each one twice to toggle the green/red lights. When you press each number keypad button - the message light should toggle on/off and you should hear a touchtone sound in the receiver. When you press the bottom non-led function keys - the message light should toggle.
This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
By continuing to use this site, you are consenting to our use of cookies.