It ain’t muted, is it? The outboard amp is on, right?
Its an analog source so every zone should receive anything the tuner captures.
Is it set ONLY to HD?
Ant connections tight?
On both ends? Ant & receiver? Winds and critters can unhook it from the ANT.
Only other thing I can think of is what band are you on?
My TX SR 805 has either 3 or 4 bands. 10 presets to each band. I forget as it only takes a minute of FM for me to remember why I quit listening to it.
Pressing the AM/FM or Tunner key…repeatedly , can’t recall which, but one for sure, until you reach the band where your presets are. Otherwise it will appear to be muted. Pulling in no channels. Or it can be done from the drop down panel on the front of the unit.
Sometimes I lay the remote down and a key gets pressed accidentally or something. Who knows.
Durect access us bt pushing the #8 or the key to the right of the zero, (_it says which on the remote itself) and then inputting the exact ch number. 99.5 = 9-9-5.
Anywho.. hope you try that and it helps. Or it magically returns to operating just fine.
Best…