You may hear no sound, muffled sound, or noise if the plug of the headphone cable is not completely connected to the input jack on the headphones. To avoid this issue, make sure to insert the plug firmly into the input jack.
- Be sure to connect the I-shaped plug into the headphones and the L-shaped plug into the connected device.
- This issue may also happen when the L-shaped plug isn't connected firmly. Disconnect the L-shaped plug from the connected device appoximately three times, and then plug it in firmly.
- If the plug isn't clean, the sound may not be heard properly. Clean the plug regularly using a dry cloth.