Try unplugging the cable power from either the back of the cable box or from the wall outlet. This usually resets the box and fixes the issue.
If after you do this and the box does not turn on, verify that the breaker switch in the electrical panel was not tripped. You can check this by either plugging in a lamp in the exact outlet. If the lamp works, the breaker did not trip. If the lamp does not turn on, the breaker might have tripped. Go to the electrical panel and check the breakers.
If the electrical outlet is working properly and the box does not turn on, then the box has gone bad. If the box turns on and says one moment please, then the box might need to receive a hit from Comcast. You can call into 1-800-266-2278 and they will send a refresh signal.
If that does not work, then you may need a tech to come out and switch the box. This will be a no charge trouble call if it is in fact the box that has the issue.
I have an MCSA cert. I have been in the IT/internet area for over 9 years. I have had many experiences in the IT field and have been in many different areas of the field. I am no longer a Comcast employee and will gladly tell it like it is to anyone. If you are not happy with your service, there are many other providers out there.
Try un plugging the box then plug back in. also make sure that power outlet does work. If it does not power on I suggest going to your local comcast payment center and get a new box. We gladly swap a troubled box.
Commercial service and installation technician, been with the company 8 years doing technical troubleshooting and installations for residential and commercial accounts. Im a front line tech and get to see more information of problems than people sitting behind a desk using scripts to help you... Follow me i can help.
Usually when your power goes out , your tv will not come back onto the correct channel , make sure you have it on the correct one first before swapping and unplugging the cable box, Does your box have a digital display ? What does it say on your box, Just incase and you never know have you tried a different electrical outlet ie changing the tv and cable box outlets , if in a surge protector try a different input there.....
Check to see if your a grounded also , You should see the main line running to the side of your house , proberly where your power comes to the side of your house. If in doubt please call a service tech out and he will check it at no charge as thats our line to fix.....
One other thing you can check is if your cable box and/or TV is plugged into a power strip, it may not have come back on. There is generally and on/off button that resets them. If it appears to be on, then move the plug for the cable box from the outlet it is on in the power strip to another outlet on the strip. I have had this work a number of times. If it is plugged directly into the wall, try another outlet and see if it will power up. Sometimes, just unplugging the box and leaving it unplugged for at least a minute or two, then plugging it back in, will allow the box to power back up.