Replaced Display Board and Battery now Touch screen not working

I followed guides to replace the Display screen from iFIXIT on my 4S iPhone as well as the battery. Other then the loss of a screw and a broken Ground clip at Battery connecter, everything went fine. When I turned on the iPhone, it loaded up and the locked slide showed at bottom however the touch screen doesn't appear to work.

From reading others it sounds like the digitizer ribbon cable or just a bad digitizer, what do i need to do to test that? Any suggestions ?