How can I arrange for a tech to come to my home to check the line to one of 4 cable boxes?

I have 4 cable boxes, after a power outage Dec. 30 night, 1 of the boxes does nothing. The power light flashes constantly and will not shut off the power.  I spent an hour Dec. 31 with U-Verse tech on the phone but he couldn't resolve the problem.  I am convinced the problem is in the Cat 5 cable feeding the cable box---NOT in the box.  The tech on the phone said he is sending me a new cable box.

I need to have a technician come to the house and check the input line.