Laser not firing

[Keith Downing]

My Boss 60W ran fine all evening (cutting and engraving) then on our last engraving stopped firing. Checked all the basics like the water flow, door interlocks, etc.

Inside the panel all the drivers for the x,y,z axis motors are on. And the lights are correct on the board I believe. Machine functions normally otherwise.

But on the main power supply neither the "P" nor the "L" is lit up; though the fan motor is running on top.

Is there a fuse or anything else I can check specific to the power supply? Before running the dreaded test that involves bypassing the tube?

In case it helps, here is a picture of the power supply in question, and there are no lights coming on. And, obviously, the test button does nothing as well.

20180119_105625.jpg

[Kev Williams]

I'm assuming you have a voltmeter and know how to use it?

but just in case

testv.jpg
--from the looks of the wiring and the diagram on the board,
the left wire is ground,
the center wire is hot,
the right wire is either hot or neutral/no volts depending on if you're 110v or 220v--

Fire up the machine, set the meter for AC volts in the 100-200 volt range, and check those terminals as shown...

If you're machine is 220v, then both the center and right wires should show around 110v each-
If you're machine is 110v, then only the center wire should show 110v-

If you DO have power at these connections, then 99% chance the power supply is toast, the remaining 1% would be an unseen fuse or something else inside...
If you DON'T have power, then the power supply is likely fine, which leaves you with testing downstream to find a fuse or bad wire that's leaving the hot line without power...

[Keith Downing]

Thanks Kev! I didn't test at the power supply, but the machine does have a meter built in; and it reads 0 when I try to pulse. Was hoping there was something else simple I was missing.

I'll try your suggestion in the morning and go from there.

[Keith Downing]

There was power at the connector, and still no lights or action from the power supply, so we're replacing it. I am a bit confused as to why the fan on the power supply still runs, but I guess something smaller on the PSU could have still failed and rendered it unable to power the laser tube.

[Kev Williams]

Just depends on where the 'bad' is. When the CPU went out in my LS900 it was getting power, and heat sinks got warm, but no fans or any other signs of life. FWIW the X driver was bad--why that would shut down most power I'm not sure, but it ain't Chinese either

[Keith Downing]

Replacing the power supply did indeed fix the problem. Just wanted to add that here for posterity's sake.

Thx again Kev.