jessabethany I'm having the same problem with an ipad 2 replaced the screen en power and volume cable's. The power button is only working when you turn the divice on or off, locking the screen issent possible olso tried by assistive touch, it won't work... Can you please help me finding an answer to this problem ?
p.s. Another strange issue is when the divece is turned on, the apple logo come's on and normally after the apple logo desepears you automatticly see the startscreen, in this case the screen stays black after the apple logo desepears untill you push the home button, could this issue have to do with te powerbutton problem ?
thx