I know that if you're on dialup or high speed that shares the same connection with the phone and you use the phone while you're online, it usually punches through your internet, making you lose signal, but not for days. A surge is possible, though highly unlikely, but that would certainly harm the modem, weather it being internal or external, dsl or dialup. It's been pretty stormy here. Has he lost electricity recently, for even a second? It fried one of my computers when the electricity went out for less than a second. It was just enough to make the lights flicker. They didn't even go out all the way. When the power went out some years ago when I had dialup, it blew up the modem from a surge. This can also happen to dsl and cable modems, but I've never had that happen. It does not matter if he has a surge protector. They don't really work unless you buy those really expensive $80 ones. I personally use battery backup and I would recommend it to everyone who has a computer. After the power goes out, I can run the computer for almost an hour on the battery backup, which gives me enough time to shut everything down and finish my projects. I have a huge battery backup system in my office which will run up to 15 computers at once and power them all for 20 minutes. In this day and age, battery backup is essential if you want to keep your computer from getting fried. B)