On the far left of the wiring compartment it can be noticed a metallic, "C shaped" tab. Close to it it can be also noticed a small plastic white cylinder. The metallic tab need to wrap over the white cylinder to ensure the flash behavior.

Notice that there are 2 little plastic tabs that block the cylinder body. You need to depress them and pull the cylinder towards you. After that, hook the metal tab over the plastic cylinder.

CAUTION: be sure to NOT touch any metal piece with your hands while following the repairing steps. Even though the camera battery was removed, discharging capacitors could still be charged and give you a considerable shock.

CAUTION: make sure the wire insulation is intact to avoid short circuits. Be also sure that no wire has unsoldered to ensure the flash functioning.