I have an I-mig 140E and yesterday it stopped initiating an arc. I thought it was maybe overheated even though the light never came on and it never shut down. I let it sit for like 30 min and it seemed to work ok. After sitting overnight I went out and tried it today and it won't initate an arc, not even directly on the ground clamp. I have only had this machine about a month. What do you think?