If you connect an external monitor to the VGA port does this work or does that also fail to display any information. If the external VGA works then it is most likely a faulty touch screen and needs to be replaced, if the VGA does not work the most likely candidate is the SBC (onboard computer) at fault though I believe there is also a PSU In the surface that could give similar symptoms. Either way I suggest you refer it to your nearest service centre.