Chosen Solution
After the screen was replaced successfully, the phone after about two weeks of functioning properly, will intermittently fade or go black, but the backlight still is turned on and the phone has power. The only way to get the display to come back online is with a soft reset holding the home button and power button until the apple logo appears. No LDI s are tripped inside the phone, appears to be in a very pristine condition. Any thoughts besides the display? This was the original issue happening with the display when I replaced it.
My initial suspicion would be the display itself. However, if you are having the exact same problem on two different displays, then that reduces the likelihood significantly. You may have an issue with the LCD driver circuit but the only way to really troubleshoot this moving forward is with known good parts and then proper board level troubleshooting if necessary.
