laser tube dead after new power supply installed

[daniel coyle]

Hello

I am pretty dependent on the help I get here so know that any reply you give will have a big impact.
I have a chinese LaserWorld brand 9060 100W machine with laser cut 5.3. 2-3 months ago the machine "mysteriously" stopped working. The laser output became really weak all of a sudden and then became less and less as I tried to diagnose. Wondering if it was the tube or the Power Supply I sent the PS out to Rabbit Laser to be diagnosed. Ray was able to tell me the PS was broken. I wanted to assume this meant the relatively new RECI 100W tube (less than 40 hours on it) was fine and I just needed to replace the PS, which I did. That all took about 10 weeks to get to so by now I am pretty behind on my work.

When the new PS came I installed it the same way the last one was installed and I got a pulsing action from it, no continuous laser. I explained this in a previous post and made a video of it. http://www.sawmillcreek.org/showthread.php?216980-Pulsing-problem-with-Chinese-Laser Basically I could not get a continuous laser from holding down the test/laser button (which worked before) or from running any of my files. Just a short pulse at the beginning of each cut path that was dictated in the file. You can see this in the video (excuse the loud obnoxious music in the background please.

I looked over my connections and cleaned things up wherever I could find an excuse to and tried again. This time the pulses were a little more erratic and sometimes lasted for a longer pulse but other than that no big change, except that the color in the laser tube was now a purple instead of a pinkish hue (or, at least, i think it used to be more pinkish) This is the video for that

https://www.youtube.com/watch?v=13i6xq0T2Fg&feature=youtu.be

I asked the chinese what was going on all along and after looking at the last video they said the tube is toast. Can anyone explain what is happening here? Did I somehow manage to destroy the tube with the new power supply? What mistakes did I make? I tried to ask for guidance outside of this site but just didn't get the responses I needed and tried to do my best going it alone.

Thanks for any and all feedback
Dan

[Dave Sheldrake]

Dan, at 0:25 it looks like there is an arc to the machine chassis,, looking closer at the video there seems to be water inside the resonator tube? that would explain the arcing and why the tube isn't firing (you have a dead short through the resonator full of water)

cheers

Dave

[daniel coyle]

Is the resonator tube the inner gaseous tube chamber in the laser tube? Does what you said mean the laser tube IS dead or ???

Thanks Dave

[Dave Sheldrake]

That's the one Dan and yes, if there is water in there the tube is very dead, if so DON'T keep hitting the button to fire the tube, you will kill the new PSU as well

cheers

Dave

[daniel coyle]

HI Dave
I took the video at night and just looked closely at the tube now. I didn't see any water. the inner tube that is for cooling has an antifreeze mixture in it and so it is that much easier to see if there were water in the resonator. Is there a better way to test the tube? I could re-check it by running the same test I did in the video in good light but don't want to risk killing the new power supply (if i haven't already.)

Dan

[Dave Sheldrake]

There's deffo something wrong Dan, there's an arc to the machine chassis at 0:25 that suggests a short somewhere.....can you post a good resolution pic of the end of the tube from the video? I'd suggest against firing the machine until we have some kind of idea of what's going on to be honest.

cheers

Dave

[daniel coyle]

HI Dave

The video here mostly tells everything I have figured out (really more like the new questions I have.) Turns out the neg wire either detached or 'burned' off the neg terminal which i am sure caused the arcing you saw

https://www.youtube.com/watch?v=9o_xNuMWDwA&feature=youtu.be

thanks for your help!

Dan

[Dave Sheldrake]

Hey Dan,

I'm thinking that a loose connection to the negative *may* have arc'd (burned the wire off) , there is usually a ferrule on the leads to the tube so the connection without one may not have been great. If you can get a couple of the disk ferrules from a local electrical shop and fit them that will help in future and *possibly* may solve the problem you are having. It's a lot of voltage so anything less than a good connection will cause problems.

Try adding the ferrules then test the tube with a quick pulse (no more than maybe 1 or 2 seconds) then we can see where to go from there :)

cheers

Dave

[daniel coyle]

Thanks Dave. Continues to be a big relief to have help here. Will get ferrules and pulse. Let you know.

[Dave Sheldrake]

No worries, I'm away for the next 3 days doing a roofing job on the new place so don't worry if I don't seem to reply for a bit :)

cheers

Dave

[daniel coyle]

well maybe this will catch you before you go. i just tested the machine further and re-attaching the neg wire solidly gave me a continuous beam! first time i have had that since installing the new power supply. the unfortunate thing is that there is a significant loss of power. the settings that used to cut through 6mm cork are now not making much impact. i would say there is definitely over 50 % loss of power. I am assuming i damaged something? If I did I don't know whether it would be the new power supply or the the newish tube. any ideas on that or how i could figure that out?

[Jerome Stanek]

Did you realign your tube after you worked on it?

[daniel coyle]

Jerome
you hit it on the head!! I think. I pulled the nozzle off and got increased power/effect. must have been hitting the nozzle head. Before putting it back on and re-aligning the beam I tried to focus the laser on the cutting surface but the z motors won't move!!! are you kidding me?! it is literally one thing after another. crazy. there is some sort of short it seems and i have little clue as to what would have caused this and how to find it. gonna ask a buddy to come help figure it out but if you have any ideas....
Dan

[Amos De Pasquale]

Here is my suggestion, You really do need to know if the tube is ok or if the new power supply is ok or faulty. Make sure all connections to tube are making good contact, make sure all mirrors and also the tube beam outlet side are clean, check alignment, and give it another go. If you have already done this, then you may need to check the new supply. If that is ok, looks like tube. The hard part is being able to have a KNOWN good tube or supply so you can decide which is faulty. Unless of course, someone here can suggest how to test the supply. Here is where good service and understanding from the manufacturer would help heaps. Amos

[Dave Sheldrake]

Hi Dan,

Have a look in the cabinet and tighten ALL the screw connections to the cards, every last one of them :) then as Amos says make sure you are all aligned and clean then try the pulse test again. You *may* have damaged the tube or PSU BUT it's not that likely unless you have left it running for an extended period while it was arcing out.

cheers

Dave

[daniel coyle]

Thanks guys. For some reason I was not able to open the sawmill creek site from my computer the past several days. The combination of advice has lead to success! I am cutting again. I did some re-alignment and tightening up of things and its all good (actually there is still some black magic kind of stuff going on but it is tolerable for now - the z motor/table doesn't want to move and seems to be shorting out and the machine sometimes trips the power surge protector in ways it hasn't previously) nonetheless, i am happy to be here saying that i am back in business. can't really say how much help this is. i would be lost!

best, dan

[daniel coyle]

wow. spoke too soon. this thing just cut out in the middle of a standard job i have been repeating since i got it up again. tripped the fuse in the electrical panel. does this again every time i try to turn it on now. some sort of short i guess. can't find it yet. is there a best way to figure this out. this thing is committed to fighting me every bit of the way. its like being in a sitcom.

[Amos De Pasquale]

Daniel, you mentioned that your Z axis refused to move?!, could it be that a faulty Z axis motor is reflecting a short and causing your fuse to blow?? Usually if a fuse blows at the power board the fault is in the main AC power section, maybe some type of leakage, do check all power cords from the mains, sorry to be all over the place, but, we have got to get it going without any strange "bugs". If I lived near you I would definitely try to come over and help, I KNOW from personal painful experience, how you feel. Amos
PS , PM sent