i used to have the same machine, this is the least of your concerns, the consumables for this machine are astronomical. never had any problems not relating to consumables with this machine. even profax parts were slightly off but still ridiculously expensive.
i always had to hit the trigger twice, the first turned on the air, the second started the arc, even if you aren't holding the torch anywhere near the work you should still get a small arc. this is not good to do as it shortens the electrode life dramatically, which leads me to believe you may need a new electrode. if its a new to you torch it would probably be a good idea to replace all the consumables so you know exactly what you've got. i had problems with profax parts not lining up exactly right and the electrode and contact tip didn't seem to make contact. i ended up tearing the torch head apart and ordering a hypertherm head that was supposed to be universal. torch head was 500$ but katrina came and destroyed the welding shop and their records of my ordering it, as well as my machine. if you can get it running, and if you find affordable parts let me know so i can stew with envy.