I have an older at&t 620 speaker phone

Intercom button/s provide dial tone when they are pressed. They are required to call other phones on your system.
Sounds like your button is stuck or issue with the motherboard.

Helo libbyc,

What is the model of your Nitsuko phone?

Feature * 3
Press that button
Feature then 0

If still an issue then do F * 0 and press that button, need to know what is says on the display as you cannot override Lines,Intercoms, Handsfree, Huntgroup keys.

Resolved

What? They are either programmed or not programmed. If the button is blank, I'm voting for NOT programmed.

If your system is old enough, it's probably lost the backup battery. Ugly things, like pulse dial and only 2 lines are what usually happens, along with losing all of the button mapping but your 2 lines and the default programs of LNR, CONF, etc.

If it's just one phone, there's no magic recall. You'll just have to reprogram it. Same with the system if you've lost everything, but I"d call a repair tech first to fix the battery on the software cartridge.

Carl

Here's a guess. Is the 7020 the one with 16 buttons? If so, they are marked CO 1-12 and F1-4. You program them by putting the phone in PROG from the switch on the back of the phone, then press the button and 1. If it's a F button, dial 9 + number and STORE. If it's a CO button dial 29 + number and STORE.

If you're talking SYSTEM speed dial numbers, those are done from the display phone at jack 01 and putting the system in programming.

Carl

What happens when you dial "9" on the intercom? If that gets you an outside line, then press PROGRAM, one of the buttons, and dial 9 plus your number and STORE.

Hmmm...Speed dial :-)

If you get a vacant line at "9", then you need to reprogram your 400 line access on your phone sytem to disable the vacant lines.

Carl

hit the options jey till you get to dss then press the button you want to program and then enter the exstension number you want it to be and then when finished press speaker button

http://support.avaya.com/edoc/docs/terminal/trm406u2.pdf

Cheers

to program a speed dial button - <feature> *1 - select button / enter speed dial number / quit....you may have to reprogram each button.