1. The volume of the units on both sides is not equal, resulting in biased sound conditions

This situation is more common in earplugs because compared to earphones, earplugs are more fragile, especially in the unit part. Many earplugs do not have a dustproof net or other design in front of the unit, so over time, substances such as dust and ear canal secretions will attach to the diaphragm, causing vibration to be blocked, resulting in uneven volume.

2. There is noise in the playing sound

This situation can be caused by several reasons. Overload use, which is caused by excessive volume and the edge of the unit diaphragm, can cause a rustling friction sound. If the diaphragm stroke is too large and causes physical damage, the earphones cannot be repaired. Therefore, it is best to use within the power range that the earphones can carry.

The internal part of the headphone cable has broken, but it has not been completely disconnected. At this time, there is poor contact, and there may be electric current or other noise from the falsely connected headphones.

There are strong interference sources near the earphones, such as mobile phones or power supplies, and there will be interference sound in the earphones, as long as they are away from a certain distance.

3. No sound from one or both units

This situation is usually caused by a broken headphone cable. The author has calculated the probability of this type of failure, and almost 90% of headphones that do not sound are caused by cable faults. The most common parts that break are in the plug and branch parts of the headphones, and some are in the part where the headphones are connected. If the plug part is broken, simply replace it with a new plug to repair it. If the part where the cable is disconnected or connected to the earphone is broken, the entire earphone cable needs to be replaced.