If the part that you just replaced is the digitizer panel
that means you might have faulty digitizer panel.
But before jumping to conclusions,i would open the phone again,
and i would disconect the cables #1 #2 and #3,and i would take out the lcd+digitizer panel assembly and set it aside.
Then i would check with a magnifier mirror,the contacts on the flat cable
#1 which is the one responsible for the digitizer panel and then i would take one of those aerosol spray cans,used for cleaning of computer keyboards and i would blow a few jets of air in the conector where the flat cable #1 goes in.That's the special one that you have to lift a small
piece of him to be able to put the cable in and then you have to slide it back down to secure the cable in place.
It might be a speck of dust or something small inside there that doesn't allow a good contact and then you don't have the bottom of the screen working,like you do now. Good luck.