I have time warner and use their modem with my network extender and it works just fine. Doubt its your modem or time warner. I have the same samsung network extender provided by verizon. In the initial setup it takes about a good 15 min to start running. Did you try attaching the additional cable gps wire they provided you? because as stated in the manual, there are places which dont receive good gps signal and you need to get gps signal for the extender to operate correctly. So if you havent, then attach the gps external antenna cable ( i dont remember if it attaches to the affixed antenna or the slot on top back where it opens) and put the receiver outside your window or near a window to get better reception. Hope this helps.