I have a small customer that is still nursing an XTS until they can afford a new phone system. They shrunk down to about 8 employees, two of which work from home. The 2 home phones are 7024D phones, and the 6 in the office are regular 3015 phones. The 2 IP phones connect in thru a LANB card.
This set up has worked fine for years now. Suddenly about a week ago, the 2 IP phones started locking up at the top of the hour, every hour. 8am, 9am, 10am, etc. The display looks normal but the speaker and hold/save buttons start flashing, and the phone is inoperable (no dial tone, buttons don't work, no calls come in). If they do nothing, the phones will come back to life after 10 minutes. If they unplug the phone and plug it back in, they get the "NO RESPONSE FROM MFIM" message, at which point if they unplug and replug one more time, then the phone starts working again. They don't need to cycle power on the KSU, but they have done that several times just for good measure, and that doesn't help.
This is one of the screwiest problems I've ever seen. I'm probably going to try swapping in a new LANB card, but I'm doubtful it will fix it. The fact that it's happening so regularly is what has me scratching my ass. I've never heard of a bad board that was doing abnormal behavior at regular intervals but works fine the rest of the time.
Anyone have any ideas?
