Chosen Solution
After a replacement of an unresponsive screen but still showed everything working the screen is completely black. I had my iphone lcd replaced and it did show at first a dim light on screen when turned on. i tried unplugging the battery then turning it back on but all it shows is a black screen. i know the phone still works because when i plug my phone up i can see a light through the crack on the inside. i think my backlight shortage is out from not unplugging the battery first from removing the four plugs but i need to know what to order to replace it, like a new logic board or backlight screen. :it doesnt show an apple logo when trying to turn on either
You probably have a defective LCD. Take it back to the person who fixed it (if you didn’t do it yourself) and have it replaced under warranty. If you need to purchase a new one you can find one here: iPhone 6 LCD and Digitizer
Back light ic chip might have been pop if the battery was not unplugged during repair or trace damage from long screw damage. I would clean the connectors and test screen again
This could be a wide range of things from a defective LCD stated to your connector plates on the logic board they are very fragile and if bent will not work properly. My suggestion is if you did this yourself is look at your quality of replacement and that might be your solution and make sure you ordered the right model number a 6 digitizer might not work with a 6s phone and vice versa
