This will happen to some iPhone users who drop iPhone in water, direct contact with heavy rain or others. You will find a DIY procedure by ifixyouri useful as your warranty does not cover water damage.

iFixYouri DIY Procedure

• It is imperative to remove the iPhone out of the water ASAP. Once the iPhone is out of the water, you want to make sure it is powered off.
• If you get a white pinwheel on the screen and it won’t turn of, you hold down the power button and home button until it turns off. In the video we failed to record it powering back on after we powered it off. We simply repeated the ‘power off process’ and moved on to the next important step; remove the SIM card.
• Once the SIM card is removed you want to put the iPhone in an uncooked bag of rice. Tighten the bag so all extra air is gone and seal it.
• Wait 48 to 76 hours after the water exposure and then try it out. If you find at that time it is not functioning properly as a result of the iPhone water damage put back in the rice and mail it to iFixYouri who specialize in fixing water damaged iPhones.