I am the marketing manager in Mobilesentrix for 4 years
"My phone stops charging around 90%"に関する回答First, restart your device and try..
"Need Help Finding Replacement Parts"に関する回答I think should contact swagtron's official site. they may help you..
"How to fix "slide to power off" screen that randomly shows up?"に関する回答I think power button is damaged from the water, you need to replace with new parts or otherwise you can manage from "AssistiveTouch" and "Home button".