Phone Dropped In Water! Turns On & Off, But Touchscreen Doesn't Work!

Hi,

First do not turn on your phone and then you need to remove the battery as soon as possible from the phone to minimize further damage.

I realize that you can’t remove the battery or anything more at this stage but as soon as you can try the following

Dis-assemble the phone and remove the battery and then dis-assemble the rest of the phone and clean all the affected parts using Isopropyl Alcohol 90%+ (available at electronics parts stores) to remove all traces of corrosion and water. Do not use "rubbing alcohol" as in some cases this is only 70% IPA or less, can contain scents and is not as effective. If you do use it, check the label to verify the amount of IPA

Here are a couple of links that describes the process.

Electronics Water Damage

Réparer un dommage causé par un liquide sur un iPhone

As always with electronics, especially surface mounted PCBs be gentle when handling and especially when brushing away the corrosion. You do not want to remove any components from the board.

Hopefully after you have done all this the phone might possibly work correctly again.

Here is a link to the ifixit guide(s) for repairing your phone.

iPhone 6s

If this process seems too daunting, take your phone to a reputable, professional phone repair service, experienced in liquid damage repair and ask for a quote for a repair. If you decide to do this, do it sooner than later.