Set top box restarting repeatedly

It is affecting my smaller box

I power cycled the box. Since then it downloads and writes software. Then it restarts. Powers up and starts downloading software, again.

It has run this loop for more than 45 minutes 

Thanks for confirming what you've done already! If the box has been in that state for that long, we're likely looking at a compromised cable box. You're welcome to swap the device at your nearest Xfinity retailer absolutely free, or if one isn't conveniently close, we'd be happy to ship one out to you. 

Please send a direct message by clicking the chat icon in the upper right corner of the page, clicking on the pen and paper icon, then entering “Xfinity Support” in the “To” section. Please include your name and address, and I'll be happy to help.

I will take it in tomorrow.

Thank you for the help .