[lebbenszki]

Hello Guys,

I have a Chinese laser cutter machine which has a strange fault. There is a control panel on the machine where I can launch the XY move, exhaust fan, air compressor and the laser power supply.
There is a "Test" button too for testing the laser beam.

I switch on the devices one by one, works everything well. But as soon as the machine starts the cutting or I push the Test button for shotting with the laser, some or all of the equipments (fan, airblow, etc) stop.
Then I switch them on again, push the Test button again, and the devices shut down again.
I have to do this 2-3 times and then everything works well. After that I can use the machine for hours without any problem. But the problem is come back every daily "first" starting.

I have made a short video about the problem:



Do you have any idea what the problem might be?

[lebbenszki]

I checked the motherboard and the wiring of the machine. There are 9 relays which switch the devices when I push the buttons.
So these relays switch down when the laser tube starts to work.



What can cause this?

[coherent]

Hard to say. Sounds like either a failing power supply, or iffy wire/connection or solder point on a board. I've seen bad plugs, connections, solder points and failing components work when warm, but fail when cold. (then again some components work when cold but not hot) The temp changes causing even microscopic expansion/contraction at a contact point can cause weird things if the connection is bad. Only thing to suggest is inspect everything well and test what connections you can with a meter.
Good luck.

[KH0UJ]

Yep probably a solder joint cracked, better resolder everything and retighten all screw connectors

[lebbenszki]

Thank you very much for your replies. Since I'm not an expert, I wanted to make sure if there is not an obvious fault that I ignore.
Then I will check all the joints and connectons, maybe I can find something.

[simmonds]

i have the more basic K40 laser, when i did a search before buying it, everyone said the build quality was terrible and to check all wires and connectors.
so i bought it and had to level the bed, and 1 wire was just twisted together the covered up with heat shield/shrink.
took me a about a hour to search and fix the problems.
hope this helps