The main power board is located directly behind the power button, screwed into the front plate.

Disconnect all the wires from the main power board by removing the white clips from their corresponding sockets mounted on the board.

For reference to replace wires, see labeled picture of main board.

LED.

DC-in board.

Battery.

Crank.

With the Philips #0 screwdriver, unscrew the four screws mounting the board to the front plate. Remove the board from the front plate. Set aside screws for reassembly.