Quick troubleshooting when the machine is not firing the laser any more.
To begin with, make sure all wires and connections are good in the machine and make sure all cables are where they should be.
1: Start the machine
Check the fuses in the back of the machine in the connector.
2: Do a test fire on the panel
If the machine fires, you dont have a problem :)
If the machine do not fire, go to 3.
3: Do a test fire on the test-button on the power supply
If the machine fires, you have a problem in the buttons, potentiometer or the cables.
If the machine do not fire, go to 4.
4: Load a file, or make a shape and try to engrave or cut it.
Only need to test for 5 seconds.
If the machine do not move or fire – you probably have a issue with the bridge rectifier (green in the picture below) and the internal fuse. It is a $1 replacement, soldering needed. Order a new one, 600V 6A is good for the rectifier.
If the machine moves, but no fire from the tube you probably have a issue with the flyback transformer (HVT). Marked red in the picture below.This is a $20 replacement. Check out ebay or aliexpress to order a new one. Open your power supply and make sure your is visually identical to the listing on Ebay/aliexpress, there is different types.