I have a NetComm 56K modem. My computer is a PentiumII 300. OS is NT4. My modem worked fine for many months. But recently, it starts having problems. It drops the connection after about 12 - 18 minutes. I tried dialing in to different servers but the results were the same. It is clear that there are no connection time limit setup on dial-in servers. I checked all parameters on local PC and could find any modem connection time limit. I also tried to re-install OS on my computer. This time I installed 98 instead NT. But the modem connection still be cut off after about 15 minutes.
I tried a new modem but the connection still could not last more than 15 minutes while previously it could last for many hours.
Can someone help? My modem is connected to COM1. Something wrong with the mother board?