White screen/Charging won't work..

So I'm really new to all this screen fixing stuff. I want to learn how and such. So I am trying to fix a iPpod 4 Generation screen which was cracked.. I got to the point where I connected the LCD and all that but when I turned it on the first time it was always white.. So I just gave up on that for the day. The next day I tried it again and that and all of a sudden the screen turned on properly.. but the screen wasn't working when I touched it.. I was about to glue it on permanently because when I pressed the screen down against the back it seemed to work, the touch and everything.. It was late so I was going to do it tomorrow.. Then today I tried putting the screen back on but when I turn it on its white again.. I try messing around putting the LCD around and nothing works.. Still white. I had it before but I don't know why its not working now. As well sometimes its not charging.. It will just stay dead and won't charge.. I finally got it to charge a bit but I can't figure out this white screen! HELP?!?!