Paslode 1st fix nailer will not fire, gas ok, battery charged, when trigger pulled can hear gas discharging? ...
Answers: Pull your book out and check the nose where on earth the nails nouns prior to being fired. It sounds similar to you may have one jammed, or slightly bent cause the safety to stick surrounded by the nose cone. As you should know, you hold to push the nose cone down on to the board in the past the Paslode will fire.
I had this begin once to one of my Paslodes. It is an easy fix. Just look at the "jammed pin section" in your book.
Remember to remove the battery-operated before working on it for safekeeping.
How long since it was cleaned? well brought-up first answer, also :)