How can I fix mom's ATT Uverse television reception?

Mom’s internet and TV is through ATT Uverse. She got a “please wait” screen and three static dots that wouldn’t go away. The TV in the other room works fine. Her TV is where the DVR is located. I tried unplugging the router, the DVR, the TV etc and leaving them unplugged to no avail. I did disaster recovery mode which redownloaded and installed the files but then I got a screen showing a red X above a numeral 1. I tried soft resets and unplugs again with no luck. Other TV still works fine despite being fed by the same receiver. What do I do?