Iphone 4 white screen? (can't do reset)?

So i have an apple iphone 4 and last night i replaced my cracked screen.
(i have done this several times before so i don't think i coudve screwed up)
i would do the home button and lock button reset, but my home button doesn't work and i use assistive touch. Its just stuck on a white screen, when i get a text or call it vibrates but i can't answer it or see it. I can switch the power off though. How can i get it back to normal?

Have you recently installed any app?

Try to sync with iTunes.