Wii U Pro Controller - questions

[Blargaman91]

My first question: Does anyone know what this connector circled in red is?

My controller doesn't have that connector. I can't imagine what it would be for since the controller doesn't seem lack anything obvious, except maybe a right rumble motor.

Secondly:This blank LED spot here, what sort of function does a third LED have there? I haven't gone and soldered an LED to it because I don't know anything about it, but I figured someone might.

 

[Bakuku]

led indicator plug maybe?

 

[E64]

Perhaps it could be a modchip connector that's if there's one that's out just saying

 

[Blargaman91]

I'm beginning to think whatever goes to that connector wouldn't actually function because there's a missing component near it. Still not sure about the LED.

EDIT: Never mind about the connector. It seems to be the connector for the rumble motor, but the motor is soldered to a different spot in some controllers.

 

[Blargaman91]

Since I didn't get much clarification I went and put a blue LED there. It seems to be a "battery OK" LED which is on when the battery is not low or charging. So I'm not sure why it was left out of the controller at all, because I kind of like it.
I tried to take some pictures but the lighting is so terrible it's not worth it.