Make sure the socket to which you connect your VisaBoost is live. Check whether the voltage indicated on VisaBoost corresponds to the local mains voltage. Check whether contact pins on VisaBoost are in proper contact with the contact points in the stand.
When the indicator on your VisaBoost still does not light up or when VisaBoost still does not charge, take it to your Philips dealer or the nearest Philips Service Centre.