I bought a K40 back in June, and had to go through 4 laser tubes. the 1st being faulty and the 2nd and 3rd being shipped improperly. the 4th one finally arrive and i installed it. i manage to cut one project out of it so i thought that was the end of my problems. i had it sitting for a while and recently i got to use it again. i transfer the machine over from a tight corner onto a large utility cart to have better access to the back of the machine, after moving it i had to calibrate the mirrors again. i noticed while calibrating the knob did not match up with the power gauge. i would turn it up to 11 to see only 6 on the screen. it thought nothing of it until i started another project and it suddenly started arcing from the end of the tube.
my assumption is that this tube is also faulty and only showed its issues over time as the seal was slowly releasing gas.
