Hey I change the digitizer on my iPad 2 then power and volume nothing was working , So I had to connect it to the pc and...

Hey I change the digitizer on my iPad 2 then power and volume nothing was working , I replace the control harness and still not working then I change the power supply board and still not working , plus it doesn't lock with the case , I have no idea what else to do , help? My iPad is the 2012 version