hi there people new to the forum and need help asap i just replaced a iphone 4 black screen the phone was working before since replacing it all what works is the backlight on the screen help me please
Is it possible that the new screen is defective? First thing you should do is go back in and be sure that the LCD/Digitizer connection is clean and solidly in place.
Where did you purchase the replacement screen? Chances are you've bought a china-cheapo knockoff that's not work a flip anyway... OEM replacements are the only way to go w/ iDevice parts.
If that's the case... it almost sounds like the socket, where the LCD/Digitizer ribbon plugs in, was damaged when you removed the original screen. Were you using the proper spudger or your fingers when removing the plug from it's socket?
Best advice I can give, using the existing parts, would be to clean the contact points w/ a degreaser. Oil from your fingers will cause quite a bit of interfance.
"Before reassembly, be sure to clean all metal-to-metal contact points on the pressure contact as well as its contact point on the rear panel with a de-greaser such as windex. The oils on your fingers have the potential to cause wireless interference issues."