This iPhone won't turn on
This iphone was gifted to me because it was sitting on a drawer for months. I would like to fix it and keep it as my second phone. So, no picture on screen, not detected by iTunes or Device Administrator. Replaced the battery because it's low voltage. Still nothing. I have a multimeter but I don't have an USB consume tester, which some people uses to check shorted boards (I suspected it could be that). Any ideas?