Connector pins diagram.

I retrieved this amplifier board from an Ion Plunge bluetooth speaker. I have no idea where I would connect the ground and power(vcc?). I am not that electronically minded when it comes to figuring out where to connect what. I do know that a the usb micro cable connected to this to charge the batteries. i have tried looking for help but haven't the slightest clue what to look for or where to look. Any help would be greatly appreciated.

read data sheet for this chip to find vcc and gnd. use a dmm set on continuity/resistance and touch the pins till you 0.00-0.02'ish or a beep.

why not use the battery connectors for power and ground? you need any controls/buttons that were in the speaker in order to control the board. exactly what was connected to the connector circled in red?

disassembly tip: freeze mist (or a "canned air" can turned upside down) will make the red glue on the connectors brittle, making unplugging the connectors much easier. just drip the liquid onto the red glue so that it gets very cold. this makes the plastic connectors brittle too, but far less brittle than the red glue