A poor signal, malfunctioning equipment, even lightning storms: the list of what negatively affects your Comcast cable reception is as long as the service provider's programming guide. When it comes to troubleshooting bad reception, the first place to start is in your own home, inspecting your equipment for signs of damage.
Cables & Connections
Comcast transmits the information for all its channels and services over coaxial cable. This cable originates at your regional Comcast service center and runs underground to a cable box in your neighborhood before reaching your home. Inside, most homes are wired with RG-6 or RG-59 coaxial cable, which transfers this signal from an exterior-mounted cable box to your set-top receiver. Any break in this cable -- whether it be from a damaged or improperly connected cable -- weakens the signal on its way to your TV set. The result is pixelated video, freeze framing and audio-video synchronization issues.
Reset Your Cable Box
When you subscribe to digital, HD or DVR cable services from Comcast, the company provides you with a set-top receiver box, often referred to simply as a cable box. These boxes, leased by Comcast for a monthly fee, are linked to your account. They make sure you receive all the channels and features for which you've paid, and prohibit you from viewing the channels and features for which you haven't subscribed. Comcast sends out software and program guide updates periodically, which are received and processed by your cable box. Sometimes, however, these updates aren't accurately or completely processed, resulting in poor video and audio quality. Resetting your box by unplugging it from its power source for up to 30 seconds forces it to automatically scan for the latest updates from Comcast.
While standard definition programming can be relayed over coaxial cable from your cable box to your television, high definition, or HD, programming requires a different kind of connection. HD receiver boxes must be connected to your TV using an HDMI cable. If your reception problems only appear on HD channels, check this HDMI cable for any damage which could compromise your signal and the images on your screen.
While satellite TV reception is often maligned for its poor quality during storms, cable TV is not completely immune from this problem. Comcast urges customers to turn off their cable box during lightning storms. Power surges caused by the lightning can send high amounts of voltage to the cable box, potentially frying its circuits. If you fail to unplug your box during a lightning storm and experience reception problems immediately afterward, reset your box.
Occasionally, even these troubleshooting steps won't resolve your poor reception problems. A defective cable box or issues with the coaxial cable wiring outside your home are problems you won't be able to resolve on your own. Instead, call a Comcast customer service representative at 1-800-COMCAST to schedule an appointment for a trained technician to evaluate the issue on site.