if the touch pane is working, it means that the touch screen digitizer and its flex cable connector contacted well with main board.
if the LCD panel is not working, it means that the LCD panel and its flex cable connector not contacted well with main board, it appeared many issues like yours.
1. connect the dock into connector in main board again, please make sure that the dock connector on LCD panel 100% contact with connector on main board!
2. if you still have the same problems, pls check the LCD digitizer assembly is compatible for your phone?
3. make sure the flex cable that is connected with lcd panel is good, have no any damage or break. error or improper cooperation will cause it during the replacement.
4. if the quality of LCD panel is poor, it cause many quality issues like black, white screen and have grids or lines on the screen. pls confirm it.