I’ve got an old Full Spectrum 4th Gen Hobby Laser I’ve upgraded with a Cohesion3D board and it works, and I cut things, but I noticed that the ammeter never went above 2 milliamps. I knew the tube was old, but that still seemed really low, and did not change when I adjusted the potentiometer.
I replaced the ammeter thinking it was faulty, but got the same results with a new one…
Finally I replaced the tube (it was many, many years old) and when doing so noticed the black low voltage return line, which I believe should go directly to the ammeter, was also connected directly to the frame of the machine, so in effect, to ground.
Would this be the reason the ammeter never goes up much? (I think it goes to 3 or 4 now with the new tube.)
My only assumption is that the low voltage line connected to the frame just as it comes out of the tube is negating the amount of current running to the ammeter… Does this sound correct? If so, should I remove that ground wire?