Chosen Solution
I just replaced the battery but When I hold the 2 volume buttons and power button it vibrates with a black screen. If I try to hard reset it the screen is still black. Holding down the home and power button does nothing, I’ve tried everything. Its on the iPhone 6s Plus
Did you disconnect the battery prior to disconnecting (or re-connecting) the screen? The 6S/6S Plus have very sensitive backlight circuits that blow easily when the battery is not properly disconnected. You can check this by connecting your phone to iTunes and then shining a bright flashlight on the screen. If you see a dim image, then you have a backlight problem. It could be the screen…and the only way to know is to try a known-good screen in it’s place. But chances are there is a logic board problem and that would require a micro-soldering repair.
