Although Comcast remote controls vary by design, use and cable box type, certain common remote-related problems occur—such as the remote only changes TV channels, brings up a blue or snowy screen, or blinks repeatedly. These are problems that almost anyone can troubleshoot without immediate professional technical support. Getting to the root of these issues doesn't have to be difficult, but it requires that you learn the different common remote issues and what causes them.
Check the batteries first. Dead or dying batteries can cause many issues. The remote may stop working, or the "mode keys" or the "red light" (if applicable) stops lighting up or blinks repeatedly when in use. Check the position of each battery—the positive (+) battery end should be aligned to the positive terminal contact and negative (-) battery end should be matched up with the negative terminal contact.
If positioned correctly, pull out the batteries, replace them with new ones (typically AA batteries) and then try your remote again.
Make sure that that you have the appropriate device selected. When you don't, numerous problems can occur. You may see a blue or snowy screen instead of a cable channel. The TV channels may change, but not the channels on the cable box.
To switch back to cable using a remote with mode keys from an auxiliary device such as a personal DVD player, point the remote at your cable box and then push the "cable" mode key. If your TV has a separate menu for switching between the TV and DVD player, push the "TV" mode key first. Then choose "Input: TV/VCR" key to switch to the correct auxiliary device input; then select the "cable" mode key to use your cable service. If you have a Comcast Digital Adapter Remote, simply select the "TV/VCR" or "input" option on your TV's remote to switch between devices.
Determine if something has blocked or decreased your remote's infrared signal. Usually the device mode key or red light blinks, but the remote won't work when this happens. Often the trim on a TV or entertainment stand, other furniture and/or decorations can block the remote's infrared signal from reaching your cable box. In addition, standing more than 15 feet from the cable box can cause this problem.
Confirm/retry the device code or try a new one. When programming your remote to work with other devices, the device mode key ("AUX" or "TV") or "red light" may not blink twice to confirm the device code. If the key doesn't blink at all or only offers one long steady blink, the remote may not work with the device.
If you go through all of the codes and you still can't program the remote, follow the instructions in your specific remote's manual for conducting a device code search. You can also contact the manufacturer to see if any other codes exist.