Optima Compact- Day light not on?

After an electrician switched off all the power to the house (including the alarm), when the power came back up, although the red 'power' light was illuminated on the Alarm Controller, the green 'day' light wasn't lit- something that seems to be a pre-requiste for using the alarm. Now everything seems to be dead. Is there a 'reset' inside the unit does anyone know?