Chosen Solution
I have a broken iPhone 7 Plus and i tried to fix it and forgot to disconnect the battery (fully discharged) before the screen cable (the screen flew out but the cable still connected to the logic board)
it’s not ideal. it’s always best to disconnect the battery first and reconnect the battery last. even if the battery is fully discharged, there may still be some residual power circulating through the circuits. i’ve accidentally forgotten the golden rule a few times with no ill-effects, so i’d say you’re probably okay. the bigger risk is with reconnecting, not disconnecting, because as you’re trying to maneuver the plug into the socket, there is a small risk of creating a short and having power flow in such a way that it could cause damage.
