In the past, it was common for silver plated parts to not be packaged, sealed, and stored for a long time in the electroplating workshop, resulting in yellowing of the silver plating layer. However, after silver plating the defective parts, they were promptly packaged and stored in dry containers, indicating that this is not affected by the factory air atmosphere. During the painting process, it was found that the entire batch of repairs were recorded on the top cover. The important reason is that the gap is not blocked, allowing the paint mist to enter and adhere to the surface of the silver layer, and cannot be removed. To prevent such malfunctions, it is recommended to seal the gaps with 3M tape during the handling process to prevent paint mist from entering.