Need to know more info. Brand, model, etc... Question is WAY too general.
You need to push the reset button.
mobile phones
How do you repair a virgin mobile phone that's turns on but can't see the screen
Setting->Options->Brightness then you set the brightness
who knows it happened to me! Answer me!
Blow into the cartridge.
Replace the LCD
If it is only his phone, tell him to clean it.
Josh has a white iPhone 4s.
The Cobalt SP500 White 5 Capacitive Touch Screen Android 4.0 cell phone appears to be a quality phone. It boasts an impressive 4-5 hour battery life, built in Wi-Fi and a high resolution display screen.
It depends... I dropped my phone and the screen turned completely white. When I brought to my phone company, they said they couldn't repair it and that I had to buy a new one. That might be different with your phone company but I would be surprised if they can't fix it. Sorry