GX CS3 acquired as a portable solution. Went in blind on this thing, so what now?😁

A local seller had it listed for a very long time so I made a low offer of $100 and he accepted. He is reseller and not an air gunner so I knew I was taking a gamble that it was a returned unit that failed the original buyer. When I picked it up I could see that it had either never been used, or that It had been perfectly repackaged with unused ties on the cords and protective material still secured to the QD fitting on the end of the whip. I still haven’t plugged it in to test it, but plan to soon by topping off one of my guns to see how things go. Anything I should do on the first run? Kind of looking for user input from owners that may or may not be covered in the printed manual. I have two much larger compressors already so my thinking is that I’ll use this when I’m away from home to supplement my gun fills from my bottles as their pressure drops.