splitter issues?

Hi All,

I most recently moved a tv I used in my bedroom into another bedroom where our family computer is plugged in. I have a splitter connecting the netgear router/modem from cox and  the tv straight from the wall. The router/modem seems to be working just fine as I am writing you using the computer the internet is hooked into, but the tv has a very snowy connection and does not seem to be working. I have been going through the channels auto preset but each time it comes back, its a snow screen on most of the channels, and a few I can see a sort of a picture but snow sound and some audio. I had the same issue in the other bedroom until I had a cox cable guy come out to fix it and he was able to get the channels in my bedroom. Now that I moved the tv , it seems to be having the same problem.... I have used other tv's in  this other room before but the computer was not connected and I wasn't using a splitter. Any suggestions? This is an older LCD tv from 2007, still in good condition. I bought a new tv in my master, so I just moved my old tv to a guest room/office.