iPhone 6 Charges but does not turn on
After completing a screen replacement the same way i've done >20 times before,
it appears that this particular iPhone refuses to turn on.
However, the screen is working because the battery with little red bars appears when you press the unlock button. It also detects whether or not it is connected to a charger, because when the charger is removed, the screen shows the 'charger disconnected' symbol.
It has less charge than what is required to turn on the iPhone.
It has been charging for well over an hour now, using 3 different cables
and power supplies.
Does anyone have any idea how to go about diagnose this and figure out what might be the fault?
Thanks you for your attention.