My iPhone 4 screen keeps flickering, and when I press the lock button a blue vertical line goes up the screen before it turns off. I can also hear crackling at times coming from the phone, even when it's off. Also, the mute/ringer icon often appears on the screen for a few seconds even when I don't touch the ringer button, and the back and front camera doesn't work, it's just black. I cracked the screen a couple weeks ago, could this have anything to do with the problems? After it broke the home button stopped working because pieces of the phone fell out around the home button, but assistive touch works fine for replacing the home button. There's also a black dot on the screen above the home button, seems to be under the screen. I know, there are a lot of problems and I'm so thankful for someone that can help in the slightest. What should I do?!