Just got an HD Cable Box from Comcast (Coax Splitter Question)
 

Ok, I just recently got another cable box from Comcast for a guest bedroom in my house. The room has a computer connected to a cable modem (also from Comcast). I connected the cable modem and cable box to a Monster Two GHz Low-Loss RF splitter.

Heres where the problem is... The cable is working for the computer, and the TV, however, all the HD channels are not coming in at all. When I hook the cable up directly between the wall and the cable box, the HD channels work perfectly... this lead me to believe that the splitter was the problem.

So, do I need a more powerful device to use as a coax splitter? Or I am just doing it wrong all together.

The TV is a Philips 32PFL5332D. I am also using pretty inexpensive HDMI cables, RCA brand I believe... but that surely shouldnt effect the cable signal.

Any help is appreciated. Let me know if you need anymore information.

I had to have two separat cable lines brought into my room to get it to work via Comcast (1 for internet and one for cable with HD). I asked about splittling the line and the installer told me it wouldn't work. I'd call Comcast and ask, my guess is you'll need a second line installed in the room.

I had a similar problem with my Comcast internet connection ... it worked when it was hooked up directly to the wall, but not when split. A technician came out and switched out the regular splitter (in/out/out) with a tap (in/out/tap), which solved it. It basically splits the signal unevenly so the cable modem got the signal strength it needed (I'm sure there's a much better technical explanation). Not sure if that will help in your case, but figured it's worth a shot.

From what I've learned working at Radio Shack, a satellite splitter may have a higher frequency and the same connectors, so you could try that.

Thanks for the responses guys... I actually picked up an RF amplifier from Best Buy and it seems to be doing the trick.

I recently got one as well. Just curious what your situation is.
Our on demand doesn't work, but we get every premium channel and aren't paying for them! Had this problem before with comcast as well. Previously on the regular digital box, our deal was to get one of the pay channels for free. But when we got on demand to work, our free channel disappeared. It was a big hassle.
This time around we're not even going to try and we'll take the premium channels since we are forced to pay 10 dollars extra just to have HD capability which I think is messed up considering it's simply a new broadcasting standard.

Sounds right. I had the same problem, two many splitters and I started to lose HD channels and other higher number channels. It was a pure signal strength issue and Comcast gave me a an amp, and everything worked fine.