Aporte original por: Josh W ,
changing the display is the best first option. Its pretty cheap and easy to do. The top part of the phone is where the LCD/digitizer connections are, so while you are changing the screen, inspect them for any corrosion. Clean any that you can see with 99% IPA and a toothbrush. Also, make sure to disconnect the battery before you disconnect the screen. If that doesn't work, then its more than likely damage to the motherboard that requires special tools and skills to fix.