Soundcard or speaker issue?

[nez]

Had this issue for a couple of years & am sick of it already.
For couple of years, every now & then the sound cracks, followed by a high pitch tone then went dead. I would need to switch off the speaker then after a few seconds turn it back on. The sound would return back to normal.
Is this speaker fault or sound card issues?

 

[Bergdale]

Grounding issue

 

[nez]

Grounding issue

of the speaker? where can i rectify this?