If you're in the middle of something, whether sending an SMS message or playing your favorite songs, and your iPhone screen begins to flicker white, it is not only distracting, it raises concerns about the condition of the phone. Some troubleshooting tips and guidelines may help you solve this hardware problem.
Turn off your iPhone by pressing the power button. In some cases, powering down the phone and then turning it back on reboots the system and solves the problem. If the screen is still flickering white or suddenly turns solid white, press and hold the "Sleep/Wake" and "Home" buttons together for at least 10 seconds or until the Apple logo or battery symbol appears on the screen. If the battery symbol doesn't appear, charge your iPhone to see if the white screen disappears.
Restoring an iPhone is a final resort that can solve most problems. Restoring your iPhone erases saved data and resets the settings. The phone is restored to the default status it was in when you purchased it. Connect your phone to iTunes and run the "Restore" utility in the "Summary" tab of the program. Before restoring your phone, back up saved data and settings from the same tab in the iTunes panel. When the restoration process completes, restore the backup to your phone.
Recommendations and Warnings
If the flickering persists, the phone could have internal damage, so it may be necessary to contact Apple support. Back up your saved data and settings before sending it to the Apple Store for additional troubleshooting and possible repair, because the technician may give you a new phone or reset the information on the old one. Trying to disassemble and fix the phone yourself is tempting but doing so may damage the iPhone further, in addition to nullifying a valid warranty if you still have one.
A flickering white screen is a problem that may appear suddenly, and it may not be because of something you have or haven't done. However, if you take care of your iPhone, you're less likely to run into problems. Charging it when the battery is running low is one necessary maintenance step. If the screen is dirty, cleaning it with a soft, slightly damp, lint-free cloth can do the phone a world of good. Try not to drop your phone. If you're a dropper, invest in a solid, sturdy case that can protect the internal and external components.