Chosen Solution
I recently replaced a screen for an iphone six that appeared dead. After closer inspection I realized the screen was still “on” however you could only notice this if you looked really hard in very dark surroundings. After trying two new LCDs the problem has persisted. The touchscreen appears to still work the screen just looks dead and even in a pitch black room you can only hardly tell it’s actually working. Has anyone else seen this? Could the issue be the brightness sensor?
Blown backlight filter. Replace it an you will be up and running.
Did you unplug the battery during unplugging and plugging in the LCD? Does the old LCD show the display properly if you try it? If the OLD LCD did show display before the replacement was done then the back light filter on the logic board was most likely blown when the screen was unplugged / plugged in.
