While over-the-air (OTA) broadcasts are typically in 1080i or 720p, the AT-163 is designed to up-convert signals to 1080p for better display on modern monitors.
First, try different HDMI cables if possible. Probably isn't the problem, but sometimes it is, and if so it's a pretty simple fix. ViewTV AT-163 - AVS Forum viewtv at163 firmware update exclusive
Plug the USB drive into the port on the front of the AT-163. While over-the-air (OTA) broadcasts are typically in 1080i
Ensure the drive is formatted correctly to FAT32. Some larger or high-speed USB 3.0 drives may not be recognized by the box's older hardware. ViewTV AT-163 - AVS Forum Plug the USB
Ensure the HDMI cable is firmly connected. If using an older projector or 4K display, check if the HDMI version is compatible, as some older ViewTV firmware may not support newer UHD specs.