Step 20: Driver Chip Sockets = 2x 16-Pins DIP IC sockets
Your kit should include sockets for your driver chips. If not, sockets are highly recommended. The most delicate thing on the ArduiNIX is the driver chip. If it encounters static damage, your ArduiNIX will output jumbled numbers. The first things to check if your ArduiNIX is not working properly are shorts on the cathodes and fried drivers. If you have used sockets, you can easily swap out the driver chips. If you have hard-soldered the drivers to the board, that is a much more difficult problem to fix.
Make sure to align the notch in the socket with the notch on the board diagram.