Loud buzzing noise from Asus laptop system speakers (and headphone output).

[kerryjtx]

ASUS (model: Desire 520) has loud buzzing noise from system speakers (and headphone output). This started as I was following online instructions to enable speakers and headphones simultaneously.
(Restart didn't help)
Sound like virus?

 

[kerryjtx]

Noise is now a ringing sound. This is a brand new laptop (purchased one week ago). Everything else working perfectly. Nothing loaded to optical drive.

 

[kerryjtx]

Saw similar compaint from another ASUS laptop owner whose problems seemed specific to battery operation. My problem unrelated to AC vs DC power.