Being able to properly troubleshoot your Comcast cable box can potentially save you the time and hassle of having to sit through lengthy calls with customer support. While not all problems have quick fixes, some can be resolved with only a few steps.
Check the connections to ensure that the box has been properly wired and is plugged in. There should be a cable wire connected to the input jack on the back of the box as well as another connection from the box to the television. This will vary based on the type of TV you have, but it can be another cable wire, audio/video cables or an HDMI cable. A power cable will run from the back of the Comcast box to an outlet as well.
Turn the power off and then back on. This will often cure problems with frozen picture or sound that either does not sync up with what's on screen or is completely inaudible.
Press the "Power" switch on the front of your box. The problem might lie with your remote. If the power goes on and you can operate the television from your box, the remote is faulty.
Remove the card sticking out of the front of the box. Reinsert it and wait while the box runs through its setup process and re-detects the channels.
Unplug the box completely, wait 30 seconds, then plug it back in again. Turn the power on and wait until the setup process is complete.