Headphone VIVANCO SR85L
Manufacturer: VIVANCO
Type: SR85L
Description of failure
Left earphone: Audio output, but very noisy. Right earbud: No signal.
Failure investigation: Cleaning the potentiometer without opening it
The fault description sounds typical for dirty potentiometers. To clean them, isopropanol is sprayed into an opening of the potentiometer and then the potentiometer is moved around generously. This softens the dirt on the running surface of the potentiometer and pushes it away so that contact is made again. Be aware, the dirt is still in the potentiometer, and has only been moved away from the contact path.
The better option is to completely disassemble the potentiometer and clean it from the inside. But be careful, sometimes it is quite difficult to reassemble them. Even if you want to open the potentiometer completely, the method presented (without opening) is a quick test to determine whether only dirt is the problem or whether the potentiometer needs to be replaced completely.