What is that old Garth Brooks song, and the Thunder Roles.
Yes the good old thump thump rumble thump, wow that brings back memories. I remember not to many years ago I said to my wife I didn't think it was supposed to rain. I kept hearing thunder off in the distance. Upon looking outside the skies were clear and nothing but stars.
Went down stairs thinking my paranormal activity had started again from about 8 years ago (MarksJohnson) remember that. Anyway, turned out it was my 600. After unplugging it for some time (can't remember how long) it magically stopped. I think it was some build up of power. The surge won't help as others have indicated, just unplug for an hour or so.
Found it MarksJ