Abstract: A drop detector is calibrated to determine a location of a detection zone thereof relative to a carriage and to each of one or more fluid-ejection mechanisms disposed within the carriage. Drop detect data is acquired for nozzles of each mechanism by indexing the carriage in relation to the detection zone and attempting to eject fluid from the nozzles, based on the location of the detection zone relative to the carriage and to each mechanism. It is determined whether the drop detector remains properly calibrated, based on the drop detect data, and repeating the method at calibrating the drop detector where the drop detector is no longer properly calibrated. It is also determined which of the nozzles are properly ejecting fluid therefrom, based on the drop detect data, and attempting to recover the nozzles that are improperly ejecting fluid therefrom.