I've replaced LCD screens on other phones in the past and from what you describe it sounds like it isn't connected up properly. The only advice I would give is to open it up again and check the cable is seated in the slot properly and check that all connections are good. From experience I've found these repairs more of a xxxxx than you would expect but generally work after a fiddle around. Sorry for the use of technical terms there
I wouldn't expect there to be any other procedure to follow other than connecting it up and booting up the phone - tho' you never can tell
Good luck
Chris