Hi there, I am having the exact same problem! I replaced my Samsung galaxy ace 2 digitizer not even 2 days ago. I had thought it went fine until I tried to power it up and the screen was just black with the model number. Plugged it into the wall to charge for a few hours, it has still just had the charging symbol on empty and not even moving. I took it apart a few times again, re-checked connections and they all appeared fine but still no power up. This is very frustrating, I'm not sure what to do next. Considering trying a factory reset but I don't know how to do it yet, still googling to get more information. I had replaced the part myself to try and save money but now it's looking like I'll have to get someone else to take a look at it. Have you had any success with yours??