I've been using my Maxstar 150stl for about a month or two now and recently noticed it making a quiet clicking/ticking sound when it is turned on. The sound comes from the back and isn't a steady click like a metronome or pocket watch but more like a random one you would hear from a geiger counter. The sound does not change when the controls are manipulated or when the unit is being used and the fan comes on. I disconnected the argon hose from the back and still no change, it functions normally and welds fine as always. just a little concerned about the noise wondering if it could be a relay or some other electronic gizmo on its way out.

Thanks for any comments, has anyone else had this experience or can you listen to your machine and see if it is noisy too?