Last night I got a phone call. The phone rang once, but nothing ever came up on caller-ID. I took a good guess and rang the person I suspected back on my cell phone. Had him call me back on the house phone. This call never arrived. I picked up several of my phones and got a very faint noise -- if it was a dial tone it was a VERY quiet one. I did not try to dial out. I went out back with a telephone and a small mag-light (since it was dark and we have a combination lock on the telephone box). Stepped off the porch, walked around the compost bin, and said "eek". My flashlight was staring a raccoon-sized possum in the eye. It was probably more startled than I, and ran back between the deck and the air conditioner and started trying to get its fat body under the deck in that corner. I saw the slats bending quite a bit, but then things got quiet, so I assumed s/he'd made it. Undid the combination, went back inside for a phillips screwdriver, opened the box and saw 2 connections. One was labelled "DSL" (oh right...) so I unplugged the other one, plugging my phone in. It worked. Okay... While I was working there (on the OTHER side of the air conditioning unit from the deck) I moved the light so I could see the corner, and there was the possum looking back at me. So I guess s/he hadn't made it, but realized I wasn't out hunting dinner, so was just going to wait me out.
Went back inside, plugged the phone in. It worked. Hmmm... Had the friend call me back on the house phone. As before it rang only once, did not come up with a caller id, but when I answered it (a few ring-spaces later) he was there. Part way through the conversation, though, it cut out. Weird. I was on a wireless, so after hanging up, I hit the "open a connection" button, and heard a beep-beep-beep noise. Hit end, then hit the "open" button again. Heard one or two more beeps, then silence. No other phones worked either. By now I was less dressed than I had been before, so I decided I'd deal with it in the morning. After the phone goes into "weird" mode, anyone dialing in gets only a busy signal.
This morning, I picked up phones to hear silence. Went outside (no possum) and plugged my phone in. Worked fine. Brought the phone inside. Worked fine. Guess it works until I'm called, then it rings once, and stops working until I unplug the house from the main. I don't much like that. One ring isn't enough to trigger the answering machine.
I figure my next experiment is to unplug all but one phone (If you count the 3 wireless phones a one unit, I have between 9 and 11), and see if the problem goes away. Then plug them back in, one at a time, to see at what point the problem returns. In my copious free time.