Original post by: Ben ,
Sorry but you need tools and this is the only way to test, otherwise take it to a repair shop to get them to test it for you. You can actually take out the screen without doing more damage to the screen frame but it's pretty tricky. I take the two pentalobe screws out on the bottom then use a razor blade on the bottom then sides to pry the screen up a bit then lift it up once it has popped up enough from left right and bottom side to start lifting it up. Note that the screen is hooked in like a clip from the top so do not pry the top of the screen. Now for an issue like this I would start off by testing another battery or trying to see if the computer detects the phone with the screen unplugged and battery plugged in. Make sure battery is unplugged when unplugging or plugging in any cables to the logic board.