Thanks for the reply, I have yet to try your suggestions but I thought I'd mention an information that I neglected to say in the original post. That info is that the earphones work OK when I'm listening to audio from other applications such as YouTube, or Skype, etc. Also I have tried the first two suggestions of making sure the plug is well seated in the jack, and the volume is up. Is this of any help in diagnosing the problem?
Thanks