Panasonic KX-TD816 shows line one in use. The line coming in is good. I have taken the line out of the system, reset the system and it comes back with line one lit up and showing line in use when you push the CO button. Even without the line being in the system. There are four telephones and I have checked all for a button being stuck with no luck. The manual does not seem to have any reference to this problem.
Thanks in advance.