My client has a Panasonic TDA50 running with 7 KX-DT343 sets. The system shows a red alarm on the KSU and all of the phones are unable to access a CO when the speaker button is pressed or when they select a pre-programmed one-touch button with an outside phone number. I am not a Panasonic tech. I am assuming that the program relating to selecting an outgoing CO is corrupted. The system is not protected by a surge suppressor and is using analog 2 CO's from the local cable company. You can press the CO button and get the line no problem, it's just the speaker button the other programmed buttons that are getting the reorder tone. Where in the programming should I be looking to restore this feature?