Retrofit a 2003 panel with a wireless converter, whole house went ghost
Tried swapping in a wireless translator on an old DSC at a rental in Phoenix and it dropped every zone signal for two days until I realized the converter needed a dedicated ground, has anyone else chased a phantom like that or was it just my bad luck?
My own version of that ghost hunt ended with me cussing at a multimeter for twenty minutes before noticing the ground screw was painted over. Old panels love to bite you on stuff the manual buries in fine print, and a floating ground on a translator will drop zones every time. At least you found it before ripping out all the wiring.