Live on the west coast. I have been getting pixling and or complete loss of channel. On about a dozen channels starting in the 40 range all the way up to the higher 3 digit channels. comcast came out and seen that the cable to the house from the pole had the outer cable cover was damaged so they replaced the cable to the house with new cable . And it seamed to fix the problem at first but now am getting the same problem again. So I don't think that was the problem. I have 3 TV's, 2 of which are connected to cable boxes, this pixling only happens to the TV's that have cable boxes . the one without works fine and I don't experience any problems. One cable box is new and the other is one that we have had for a little while. Could this be a problem with the cable box ??? In the mean time I will make a note of which channels that do this
It sounds like a signal strength problem. Check your connections and splitters. You can check the signal strength to the boxes by turning them off while tuned to one of the "bad" channels and immediately hitting the "OK/Select" button on the remote. The diagnostics will come up on the TV. Select "In-band Status" and look at the SNR number. It should be in the mid 30s. If it's low, you'll need to check your cable wiring.