In order to achieve the above and other objectives, the present disclosure further provides a method of assembling an electronic device. The method comprises the steps of: providing a casing, a base, a waterproof component, a movable latch lid and a coupling element, the casing having an opening, the base being penetrated by a through hole, the movable latch lid being penetrated by a passage, and the coupling element comprising a rod portion and a head portion disposed at one end of the rod portion; positioning the waterproof component on a side of the base and positioning the movable latch lid on another side of the base; passing the rod portion through the passage and then through the through hole, allowing the head portion to stop at an outer side of the passage, allowing the other end of the rod portion to be fixed to the waterproof component, allowing the movable latch lid to slide along the rod portion through the passage; and connecting pivotally the base to a side of the opening.

The present disclosure further has advantages described below. With the positioning posts being penetratingly disposed at the through holes, not only are the supportive sheet metal and the waterproof component positioned by each other, they are also fastened together by the bolts to fix the movable latch lid and the waterproof component to each other. The length of extension of the passage places limitations on the displacement of the movable latch lid. By moving the movable latch lid, it is feasible for the latch portion to be latched into or removed from a fastening groove, such that the waterproof lid structure gets fastened or released. Furthermore, with the resilient hook being engagingly fitted to the left and right sides of the dowel, users can confirm whether the movable latch lid has been moved to a fastening position or a release position.