Chosen Solution
I received an iPhone 6 to fix from a coworker. I plugged it into the wall, okay so the apple logo appears, then it goes to a black screen which still looks lit up. I unplug it, it turns off immediately. I attempted to plug it into my computer, it doesn’t turn on. I tried holding the home button, power and home button, volume and home button, and power and volume button. None of these seemed to turn it on. I am guessing the battery is the problem, however, I am not too sure. I am not sure if it was water damaged or not. I heard water damage could be a problem. If this is because of water damage, what would I replace? The display works fine. All signs lead to the battery, I just need a second opinion.
If the iPhone has a battery taking charge and a good working cable it should show the battery charging logo or boot to main screen as soon as you plug in a power source. Since that seems not to work, opening the phone and checking the inner conditions would be a first step..ask the owner about past liquid damage and check for signs inside the housing. If clean replace the battery first. If you have liquid contamination chances to clean it properly and get it back working without tools and experience are very, very small.
Leave it plugged in for a couple of hours so it can charge up. If you have a Mac, you can see the condition of the battery by using Coconut Battery https://www.coconut-flavour.com/coconutb…
