CNC plasma ARC BREAK ALARM

I just got my cnc plasma machine from china, as I tried to get it up for running there is problem that I have and I hope someone can help.

when I tried to cut a piece of metal, it doesn't start, it keep popes up message box say " ARC BREAK ALARM" I tried it manually the arc work. sometime the machine runs but not arc, doesn't cut at all. any idea work could be wrong? I was told be the guy who I bought it from I need to clamp it on the material not on the bed, and I need to adjust the voltage higher. Is that right?

Anything will help. Thanks