I have a 100 that is okay until I start programming station buttons. I am using 28 and 18 button phones. the software rv onthe cabinet is 1.43. after i use system button programming or station button programming I cannot intercom between stations or call the voice mail to retrieve messages. I have even programmed 1 button at a time to see which button affecting the system and it is the redial button. The customer had the button moved when they first bought the system.

Make sure you haven't deleted the Call keys.
You'll need at least one (1) to intercom.

As Hi-C said. Also, if you are lacking a CALL or buttons the display will show "unavail.CBT" or something similar.

The system worked without the call buttons before the power supply went down but I think the originalphone guy uploaded the button programming and about 200 speed dial numbers at the same time. most of the buttons are being used for speed dial locations with a few dss buttons thrown in for the door phones and the other out buildings.

The system may have worked but without at least 1 call key per phone you won't be able to make any intercom calls as stated above.

A trick we sometimes did with those phones (although I wouldn't recommend it) was to program the dss add-on buttons, although the dss was not actually connected the buttons were still programmable and we would use them for the call keys, this meant the customer effectively got more buttons, the down side was if you didn't have trunk keys and put a call on hold, it was placed on a call key which did not have a phyiscal button.

We program buttons 21 & 25 as call keys and 22 & 26 as voicemail transfer and message keys, this leaves all the keys above the dial pad for customer selection. We also program call keys on the 14 button add-on when we need more keys. This will bite you in the back-side when the customer decides to purchase the 14 button add-on and only gets 12 buttons.