Here are few tips for the recalibration:
1. Make sure the feeder sound is on (low medium or hi setting) using the volume button on the side of the feeder. NOTE: if calibration is attempted on MUTED volume (middle button on the feeder) the lights will continue to flash and the battery must be pulled to reset the machine. To change volume on the feeder press and release the middle button to cycle through LOW,MED,HI, MUTE on the volume..during the recalibration use LOW,MED or HI volume.
2. The batteries should be fresh. And calibration should be done with batteries not wall power.
3. Clean off the kibble detector(with a dry cloth) which is located just below the brushes. (3 dots of plastic in an oval on the plate)
4. Set the unit on the floor and avoid having bright light shine into the front during the recalibration