Trying to find the king of Amagal.  Chiyo's  magical knowledge is 55 yet i can't fix the circuit in the cellar of Yang tower!

it says 'Doesn't seem to work'... 

Any help is much appreciated

You're not far enough in the main story yet, to know you need to to fix that hexagon. Only after Varea tells you about will the necessary dialog appear for Chiyo to fix it.