Whinning noise @ serpentine belt area.

What is your question?

Notice a whinning noise coming from the serpentine belt location. Noise mostly during idle & acceleration. Was told by a friend that owns the same year Jetta, who also had the same problem, said that the Idler pulleys (upper / lower) & both tensioner pulleys where going bad. I went ahead & changed out the pulleys & serpentine belt but still getting the whinning noise. Any suggestions of what might be causing the noise? Jason