[diyengineer]

Just picked up a surplus universal laser system vls3.5 unknown wattage. Have to pick it up next week. Anyone got one?

[diyengineer]

40 watts

[diyengineer]

Downdraft table

[diyengineer]

Tried turning it on. Replaced a 9v battery that was dead, and checked the fuses. No start. Read on another forum it won't start unless the usb is hooked up and windows is running.. I'll try again tomorrow.

[diyengineer]

Ok, got her fired up. Corel installed, and laser control software installed. Machine jogs around, and seems to do everything just fine except mark material! Cleaned the optics and machine. When door is open red laser light appears. Close door, laser goes out. Sent a file to it, machine moves like normal but doesn't mark. Anyone have any ideas?

[KeithOKC]

Out of focus, dirty mirrors, laser out of alignment. I'd check all of those.

[diyengineer]

Decently clean. Tested at 100% bypassed the mirrors and put tape over the output of the laser.. no marks of any kind. When I manually fire the laser I can hear a high pitch noise so I know it's attempting to fire, but nothing at all. Videos to come.

[diyengineer]

https://youtu.be/dHKcYFVdqXk

[diyengineer]

https://youtu.be/T0khWdf21uw

[KeithOKC]

Just picked up a surplus universal laser system vls3.5 unknown wattage. Have to pick it up next week. Anyone got one?

It's likely the tube or power supply then I'd call universal

[MechanoMan]

I have done a LOT of technical maintenance on the ULS systems. But I haven't seen a VLS myself.

The ULR-40 is an RF laser. It takes in low voltage DC into an RF generator built into the tube. The "tube" has no glass, it's an aluminum resonator full of low-pressure CO2. It's 40W.

The laser needs 48v, an interlock signal, and a "fire" signal. It's certainly worth checking for 48v. The interlock is closely wired with the way the controller sees interlocks- that is, if the system thinks the lid is closed and all that, the tube should think the interlock's ready too.

The ULR-40 tube does NOT provide feedback to the system. IIRC it has an "ok" signal but it's not useful, if the tube isn't firing because the gas is bad, it won't know.

However, it is likely the tube needs to be regassed. Contaminating air seeps into the low-pressure CO2. Early on, it manifests as a beam that starts strong but fades out after a few minutes, even stopping completely. Later on, they just won't fire at all. I've also seen the RF stage fail resulting in a no-fire. I think I see "2007" on the label- it would be VERY rare for a laser to last 9 yrs without regassing, even when left stored on the shelf. ULS can do swaps, but I do highly recommend Evergreen Laser for regassing (not RF supply repair, though).


But something's weird. The red dot usually only lights when the lid is open. It does NOT use the red dot when cutting (though I've seen a ULS that actually did leave it on while cutting in certain circumstances). The red dot is from an ordinary 5mw laser diode, it is totally not the CO2 laser which is invisible.

I had a rare XL12000 ULS laser which had a mysterious "red dot" option- when selected, it actually disabled the CO2 laser and just ran the job with ONLY the red dot. Took me awhile to figure out why it's not running.

Now there's not only an interlock on the lid, but also the laser cover in back. If any switch is open, the laser will NOT fire. However, it won't make a "noise" either, and the panel should read that the door's open.
If there's a panel option to run the job "red dot only", it won't make a noise.

But, see, if the tube needs regassing, it will TRY to fire it, which could explain the noise, but NOT the red dot staying on.

Well, that's a mystery. I've excluded all 3 possibilities here...

[diyengineer]

The laser red dot was only on because I had it manually turned on in the software. I didn't see any switch or wiring on the rear or side access panels. I'll check for 48v.

[MechanoMan]

There's usually an interlock on the panel over the laser compartment. But there may not be one on a VLS.

What year is that laser? I think I see "2007".

The big connector on the ULR-40 laser is where it needs to be checked. However, don't remove or reinsert that connector with the system power on. You can remove the connector and THEN power up the system (obviously the laser can't fire), and ONLY replace the connector once you turn off the power.

[diyengineer]

No interlock on rear or side panels. Year is 2007. Powered off and unplugged main laser connector. The machine knows it's disconnected but shows "door open". Tested the two large pins for 48vdc. Showed 47.8v. Turned back off, plugged in. Fired it up. This time with the down draft table plugged in. Open door error went away, so I can for sure say they have a wire in that harness that will show an error if unplugged.

[diyengineer]

[MechanoMan]

So how did you "test fire" the laser before? Were you using the alignment mode?

[diyengineer]

Yes, using alignment mode. Called and it's about $1800 for a recharge through ULS. Called a local guy and we will see what they quote.

[MechanoMan]

Yeah aside from the "why is the red dot still on" question, I would just say the tube needs to be regassed. Tube don't usually last 9 yrs without a refill.

Talk to Evergreen Laser:

Evergreen Laser Corporation The Leader in Laser Repair