Chosen Solution

One of mine extra bass stereo headphones NK-XB 510A isnt working but other is,can you tell me how to fix it.

If you can hear a slight amount of sound, it typically means the wire is loose from the speaker inside the earbud. If you cannot hear anything, that usually means; A. The wire has been disconnected from the speaker and needs reattached. Or B. The speaker has blown itself. As far as I know, there is only two ways to fix this problem;

  1. Tear down the earphones and try to manually reconnect or adjust the connection. Or
  2. Order another pair of earbuds. Best Regards, Drew