I have a 2-way coax splitter connected right where the coax enters my house. The splitter is a radio shack 5-1100MHz splitter; one output goes to my cable modem, the other to a TV. I have been using this setup for almost a year now with no problems.

Then this morning my internet wasn't working so I checked the modem, it was aquiring a downstream link but not upstream--so I called the provider and they said they didn't know of any problems on their end. So I figured I'd try and eliminate what I could on my end. I removed the 2-way splitter and connected the coax cable from the cable modem (which was connected to the splitter output) directly to the coax where the splitter was attached. And then the cable modem worked correctly again! Did my splitter somehow go bad? The TV hooked to the other output leg of the splitter still works fine with good reception.

Thanks!