I suspect you have a bad control panel which. You can try for a new one or many are replacing the panel with the pot.
I can walk you through measurements to further prove the panel is bad.
@donkjr
Hi Don,
Yes it is the digital control panel with the push buttons. It’s actually just a wiring connections diagram but atleast I can confirm proper connectons. I also like the idea of going to a potentiometer. Thanks for your support!
@Tim_Robertson
The laser will nerver test fire at the control panel, the LED’s come on, laser enable and power adjust buttons function, digits change with power adjustments. All appears normal accpted for test fire at the panel and test fire being dissabled at the power supply when panel is connected. Thanks again!
I have a same issue, grab a brand new crappy chineeeese piece of s*t k40. (This was a total waist of money - to dealing with k40 seems only for masochist). Set up the optical pathway as the manufacturers set up was actually dangerous, and fireing only in test mode. Now Im go through many stages, and finally in direct contact with the manufacturer what a hell is there. I bet the Power unit cause the issue: there are a 4 connectors link between the Power unit and the Control Board. I measured a solid 8 Volts at the GND and L /the triggering signal port/ when NO program runs, and a jumping 9ish Volts when a program running. It seems the Control Board working well, generate the triggering signal to drive the laser tube. And the XY movements of the head are perfect. I believe the issue is the Power unit high initial 8 Volts potential on the L port. I just waiting for the manufacturers response.
There are many variations on the K40 theme. I suggest starting a new thread in this category and sharing pictures of your machine and electronics to avoid misunderstandings.