Make the call , They are the only ones that know how the machine is configured in order to make a quik diagnostic repair. The rest of us would have to guess.
IS this a new machine or it just started doing this?? SOunds like it is NOT getting the ARC good signal to Mach for it to start the program runnning.
Do you have the ground cable hooked to the material
? IF not you may be only getting the pilot arc not teh cutting arc.
Just a thought, (;-) TP