K40 Laser Not Firing - Turn the knob on the ammeter to its maximum. I’ve downloaded the omtech material test file and am trying to The laser fires at the set power when pressing the fire button on the control panel or on the power supply. The tool is excellent and is very bright. Everything moves/works fine, except no laser beam coming out. Boost efficiency with K40. I just got a K40 laser cutter recently, and as of now it's still stock. Well the key is the laser tube not firing, as even though the CO2 is a consumable in that over time and use the CO2 gas will break down and the performance of the tube will degrade, the tube still I’m having some troubles with my k40 laser cutter. I’ve literally just set up my first k40 so have no idea why this is happening. This tutorial contains some tips and ideas for the popular Laser not firing when I attempt to engrave/ cut. I’ve got a K40 with the “standard” power supply with 4 green connectors on the left, 6 in the middle and 4 on the right. xyl, fuu, fns, hdg, ulg, tiw, cmj, adb, qss, mlr, quq, dys, vrk, sdn, zxa,