Most the time when the LCD does not power on during the modding process the cables have pulled out of the back of the LCD itself that attach to the LCD Driver. To test, hook the factory A1U pcb and control panel back in and see if you have a screen now. If not, then the cables have more then likely came loose. To correct this:
Unhook the lcd driver from the back of the lcd then take off the front plexi cover over the frot of the lcd and remove it from the machine. There are 2 screws on each end of the lcd (left and right side), remove those then pull the back panel up. Trace the wires that hook to the lcd driver now to the back of the lcd, are the wires still connected to the lcd? if not push them in and apply tape. If they are please contact us for more support.