Regardless of the 3.5 mono plug, if it is not used for a long time, its surface will be oxidized, which will lead to poor contact. Therefore, it should be protected if it is not used for a long time. At present, many audio input and output devices will have plug sleeves when they are purchased, and use that protection. If the plug has been oxidized, the following methods can be used:
1. Use dilute hydrochloric acid, which is very dilute. Use a paper cup to hold a glass of water, dip a glass rod in concentrated hydrochloric acid, and shake it in the water (be careful when handling, don’t shake it all over the world, and be sure to stay away from concentrated hydrochloric acid Bottle mouth), shake it a few more times, then soak the whole plug in. It will be fine for a long time, because silver and copper and hydrochloric acid will not react, then take it out and wipe it dry.
2. Wipe gently with toothpaste, wipe gently, and wipe for a while. If you use force, the coating may be scratched, and if you scratch, the contact will be poor.
3. Wipe with cardboard, don't follow the lines, but also wipe lightly
4. Use an eraser, this one needs to be hard, but it is not easy to wipe, and some places may not be wiped
5. Sandpaper, fine sandpaper is better, coarse sandpaper will die, don't use this method for 3.5 mono plug.