Originally Posted by
MrMusk
We had the same thing on ours. We found out our tube was dead, one of the guys ran it not knowing that the water wasn't working and the water alarm didn't sound. so he killed the tube and the power supply.
Basically if the tube is dead, you have the massive voltage from the power supply coming into the laser with no where to go, so it arcs to body through the positive wire.
If you have fired it multiple time and it has arced you might have cooked your power supply too.