Getting aggravated with MSNBC (channel 901) occasionally freezing or going blank... yesterday I went to the comcast store and exchanged my kitchen HD box for a new one. I installed the box, and within hours the reception on MSNBC went from some static to totally freezing and pixelating with voice coming and going. It's not the tv, it works fine on all other channels I tried. It's not our cable connection because all the other boxes are working fine. The cable was installed by the Comcast tech, so was the splitter... about a year or more ago. The tv is about a year old... so this is frustrating. It's especially frustrating to see dozens and dozens of similar problems with MSNBC all over the country.
It's pretty much unwatchable, and it seems like a systemic comcast problem, otherwise every channel would exhibit the same problems. Everybody 10 seconds my picture on a UHD Samsung looks like the attached picture, and no voice.
@Mike_MASS wrote: ... it seems like a systemic comcast problem, otherwise every channel would exhibit the same problems ...
You would think so, but the causes of these kinds of audio and video problems can affect a single channel, a group of channels, or all channels. All it takes is for the signal for the channel you are trying to watch to be too weak or have too much noise. Since your other sets are OK, most likely there is a poor connection somewhere along the coax line to that cable box. A bad cable box is also possible, but that's less likely.
Troubleshoot by checking the connectors at both ends of that coax cable for corrosion and tightness, and by looking for damage. Running the cable through a surge protector, a defective splitter, or too many splitters can cause signal problems as well. If there is an amplifier in the line make sure it's getting power.
If you can't find the problem, call them at the phone number on your bill or 1-800-Comcast, or chat with them using the TV Support option at https://support.xfinity.com/chat. Ask them to check the account setup and send a refresh signal to the box. If they can't fix the problem remotely, insist they send a tech out to identify the cause and correct it.
If the tech finds bad coax, splitters, amplifiers, or connections in your home (even if Comcast originally supplied them) you'll probably have to pay for the visit.