How to reset a CTB16PC depends on the version of the board.
For older boards you will find a row of pins with a jumper to the right of the CAT5 connectors. Unplug the power, remove the jumper, plug in the controller (you will get a fast blink), unplug the controller again, and replace the jumper.
For new G3 controllers there is a row of pins to the left of the CAT5 connectors. Unplug the power, move the jumper to the right (onto pins 5&6), plug in the controller (you will get a fast blink), unplug the controller again, and move the jumper back to pins 4&5.