Under the charging port cable, we strike daughterboard. Eureka!

The little foam foundation is the speaker box for that loudspeaker we spied in the midframe.

The daughterboard also houses a familiar classic: a coin-style vibration motor. Unfortunately, you'll need a soldering iron to replace it.

On the backside we find yet more spring contacts, a microphone, and the soft button LEDs. Like the motherboard, this daughter is a busy board.