I had a simular problem with my cable modem where it would go out for hours on end. After calling the cable provider (comcast) and after several diagonstic steps they sent someone out who replaced my modem. That worked for about a month. I also bought a radio shack splitter which worked for a while then would go out whenever it felt like. After I was told all of my cable wiring needed to be replaced (the wiring was only 8 months old) I added a signal booster from motorola and never had a problem since. This is not a splitetr. The cable goes in and a connection goes out. This unit can be installed before the soplitter or after. I bought mine at Best Buy.

By the way I was told from comcast that most of radio shacks items are poorly made and may hurt your signal not help it. I don't know if it is true or not.

Hope this helps