Chosen Solution
I recently replaced the microphone, charging section of an iPhone 6 4.7. Upon placing the screen back on, I received odd grey bars that extend to just below the clock and battery indicator. What could this be?
Remove the screen, remove the connectors from the motherboard, sounds like one of the connectors is not attached correctly. When you connect those connectors they should make a click sounds just like putting Legos together. Put everything back together and you should be all good.
Does the screen sit properly in the case? What does the bar when you touch the glass with little (!!!) pressure of your finger?
