A dust-proof telecommunication system and a method for assembling a dust-proof mechanism are disclosed. The system includes a chassis including an opening on a top side thereof; a PCB located within the chassis; a memory module removably installed on the PCB; and a cover removably coupled to the top side of the chassis. The opening is positioned and shaped such that the memory module is accessible via the opening for easy replacement. The method includes inserting a strip into the opening such that a space is formed between a wall of the opening and the strip; and inserting the memory module into the space formed between the wall of the opening and the strip such that another strip located at a first side of the memory module contacts the wall and the strip contacts a second side of the memory module. The memory module is replaceably coupled to the PCB.