Restart Xfinity Box with Black TV screen

Sometimes when I return to my TV, the Xfinity cable box has received an update and my Xfinity box will still be ON (with the indicator light shining) but the TV HDMI input will no longer recognize the cable box. The TV screen is completely black and not showing the Xfinity screen/cable. Turning off the TV does not help. Changing the input of the TV does not help. The only way I can get my TV to recognize the Xfinity HDMI cable box again is to unplug the cable box from power so that it turns off. Then I have to fumble around with cords to get it plugged back in to the power source.

I have tried using the Voice Command button on the remote to reboot or restart the Xfinity box BUT the TV screen is completely black, so I cannot follow on screen prompts. Pressing the Power button on my Xfinity remote turns my TV off and does not turn off the Xfinity box. 

My Question: Is there a way to reboot or restart the Xfinity box using the remote only? Maybe a button combination or specific voice command.  

Thanks!