We have 2 phone lines coming into our house and two phones on each. The phones are all Panasonic A144ES. Yesterday morning when we received our usual "I'm still breathing" call from Phyllis, all our phones went into meltdown. We couldn't get them to receive a call, or make one. After some effort, and I don't know what he did, Dez has made 3 of the 4 work again. However, there is still one stubborn git of a phone which doesn't. I can pick it up and get a dialling tone, but when I try to phone out it gives the type of signal that indicates that the other phone on that line is in use. When we get a call on that line, that particular phone remains silent.
This is a total mystery to me. Does the panel have any bright ideas?