This is a troublesome step, since the LCD connector is particularly difficult to reconnect, and know that you've gotten it on. And thanks to the note claiming that if it's disconnected, if you might just get a black screen, you're left with having to disassemble the entire unit again, without knowing if it's powered off (since you presumably tried to power on). That's also nerve-wracking. I had this problem and disassembled and reassembled the entire phone, only to have the problem again. On the second try, I plugged the phone into power, and after a little bit, got the dead battery screen showing. So the problem was that the battery was discharged, not that I'd biffed the LCD connector.
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