Digital TV service from Comcast can sometimes develop problems. Signal problems, where the TV either has no signal, or signals are not working properly, giving odd results in a show, like voices and lips not matching up or signals that come and go, require troubleshooting.
1. Read any messages on the TV screen. Some Comcast channels might not be available or are not part of your package. When one of these channels does not play, the channel will display a message. If there is no message and the channel does not play, the problem is related to the signal.
2. Check the cables. If cables are loose but still attached, there will be a signal, but it might come and go. Push loose cable firmly in place, and the signal should improve.
3. Unplug the cable box. Leave it unplugged for one to two minutes, then plug it back in. Turn the cable box back on, allow it to load, and check the signal. This simple procedure can fix many problems.
4. If problems persist, call the Comcast customer service number and speak to a representative. If your problems relate to HD transmission, make sure HD is included in your package. If the problems are not related to an HD transmission, set up an appointment for a technician to come over. The cords might have breaks or problems which require new equipment to fix the signal problems.