iPhone was exposed to water for maybe 2-3 seconds, pulled out immediately, put in rice. Tried to turn off but screen wasn't working. The phone sat in rice overnight, but was continuing to get notifications throughout the night and my wakeup alarm went off as usual.
Decided to take it out of the rice, check it out. Phone seemed to be running as usual except the screen was totally black. Popped out the SIM card to check if any water there, and the screen turned on, with a few black vertical lines on the right side. Worked for about twenty minutes, then went black again, although the phone didn't stop getting notifications.
Soft reset brought the screen back.
Gradually more lines have been appearing, thin white ones this time. Turned phone off, when turned back on, screen is black again. Was able to unlock to backup on iTunes only because somehow the touch is still working even though the screen is black.
I have been researching how to replace screen on 6s, but it's not worth it if the phone is a goner anyway. Would love any advice.
Best Answer
Rice may have worked on much older devices. The iPhone 4 and later have so small physical gaps, that if liquid gets past the liquid indicator sensors, you will need to desolder parts off the logic board and wash / repair the corrosion that happens in a matter of hours (worst case) or when drying (best case).
Unless you need data off the device, it's best to get it to professional level repair or replace it when it fails to start like yours does now. Display problems indicate that power lines are shorted or corroded internally.