Why does a newly replaced digitizer loses ability to recognize touch?

Hello, I replaced the digitizer to a second iteration of the iPad 2 for a client, and after awhile it can loses the ability to pick up any touches. When I received it and opened it up and I went ahead to put in some extra screws to hold down the LCD screen. I figured that would help keep in place the ribbon cable to the digitizer, but no dice. I had him try a hard reset by holding the lock and home buttons simultaneously, but I get the same result. I'm going to get him to do a system restore through iTunes, but at this by point, I am running out of options. I am starting to think that it could be a faulty Logic Board. Any ideas would be more than welcomed.