to "turn on" the n3i. It's definitely the two on the left and either the upper or lower on the right. I had the same problem with my N3i and the
Suunto tech dept. helped me out with this because the instructions are poorly written. Once you do this you will see the screen come to life and the charging indicator will appear.
I don't have the watch anymore because it wasn't working out for me but I still think it's a great piece for those who can use it. Good luck.