Xfinity TV box showing first “boot” then “CASE” and finally stuck “PSt”.

That means the box doesn’t have a working cable signal. Did it ever work?

Hi @user_69b7dd, thanks for posting to our forums. Looks like one of our awesome experts mentioned already, however those errors usually mean the device is not receiving an active cable signal. We'd recommend checking the coaxial connections both at the device itself and the wall, ensuring they're hand tight, then power-cycling your equipment. You can find troubleshooting tips and tricks on our support pages here; https://comca.st/3gILDPv