Not able to get ABC CBS NBC or even low channel 165 LOGO ON X1 box

Hi there. Have never had this problem before and called comcast . have sent refresh signal and rebooted box several times.  Has a code but can't remember it.  Message says " We're having a problem on our end. Please try channel in a few minutes."  Its been 2 days. Have a tech schduled for tomorrow.    Same channels don't even work on a plain digital adapter box.  Those same channels say the signal has been interupted.   ANy ideas??  I am in Naples FL.