Have (3) AM-21's Hooked up for OTA One is hooked to a HR21/700 other a HR23/700.(2sets) Never had any problems for close to a Year. Neither Receiver is now pulling the OTA Channels/signal. Guide Info is there in both but when turn to an OTA you get a phrase searching for signal in the off air tuner(792) I went into the Settings and went back to the initial setup reset the settings for OTA nothing changed. I unplugged the AM21 and let it reset by a reboot still getting the same message. Any help is/would be greatly appreciated.