300 watt dual tube, both tubes not firing at same time

I bought a 4’ x 8’ 300 watt laser 2 years ago, The tube was broken by an accident in the shop. I purchased a new 300 watt dual tube, installed it, aligned it. The machine will cut but not with both tubes at once. The top tube will file sometimes, the bottom tube sometimes on a rare occasion both tubes fire and it is like the skys opened and the beam cuts great. one tube at a time will fire 58mA whenb both fire it is about 18mA. I have tried wiring CN6 to one power supply and CN7 to the other, the machime was originally looped between the 2 power supplies. I have been messing with this for about 6 months now. Very frustrated. So to re cap. New 300 watt dual tube, 2 new 150 watt power supplies and a new Rudia 6334M controller. Any help would be great.

Did you follow the Ruida diagrams for wiring the separate supplies…?

Don’t have a clue how this would be wired…

How does one mA meter measure both tubes… you have to clarify what this means or at least, how it works.

The Ruida can control two tubes, but the manuals usually show them suffixed as 1 or 2 in the connections… such as WP1 and WP2

Here is a diagram from my Ruida 6332G manual… rdc6332g.pdf.txt (2.9 MB)


Yes, that is how it is wired, but both tubes do not fire at the same time, its weird. One tube will fire, next cut sometimes the other tube will fire. on occasion both will fire. It will cut 1’’ acrylic in one pass so I assume both tubes are firing. I just do not see the beam thru the tube, I don’t know if I should see the beam in both tubes.

You can’t see the actual beam, but you can see the pink color ionized gasses.

They should look similar when they lase…

How is the mA meter wired into this?

You need to read each tube with it’s own meter to know what the tube is drawing.


The tubes do not look similar whan cutting, one tube will be a bright red where as the other just looks like clear glass. The mA readings show the same from each power supply. But I have trouble cutting they 1/2’’ acrylic.

Could you post a photo?


It doesn’t look like it’s lasing.

I don’t have a dual setup, but does it have some kind of lps for each tube?

Does the non lasing tube in the photo work by itself?

I know how the signals work, but don’t really have any experience with how to set a dual tube up.

If it’s been working and this is a hardware issue, maybe we can help, but we need more information on the machine…


since I have it, it has never worked correctly. each tube will work at random times, mainly the bottom tube fires. I have new power supplies, new control panel, the tube is new, just never any luck getting it right

Unfortunately I don’t have anything like this, so I don’t know what to advise or whom to check with…

The only thing I could think of is watch the inputs to the lps and see if they are correct…

I don’t know how they are supposed to operate… sorry about that…


I just want to know how many houses I have to remortgage to get that tube. :smiley:

Its broken forever sorry to say. Now where can I go to pickup this free broken 4 x 8 table from your shop :star_struck:

@ JKWilborn, thanks for trying. I know I have limited experiance with lasers, but this makes no sence to me.

@ Rob H. was not too bad $2800 from Alibaba about 10 day delivery.

@ Mountaineer Trader. It is getting to that point… lol

Hi Chris,
What is the make & model number of your HVPSUs?

So, are you saying they were both wired to the same inputs originally?

when I got the machine, both 150 watt power supplies were wired to CN6 only, I now have one to CN6 and one to CN7. Still no luck. I do not know what HVPPSU is?

HVPSU =high voltage power supply unit.
You’ve said that both tubes will fire so that means both tubes & power supplies must be working, so that means the problem is most likely a control issue.
I suspect that either your controller settings are wrong or the control circuit is wired wrong. I do know that the controller you have is special purposed for metal cutting. I also know that you don’t have the power supplies connected the same as the ones you replaced. I am assuming that the laser was working before the tube got broken. Do you have any photos or wiring diagrams of the circuitry before you started replacing things? it would be helpful if you have the old supplies if you could get photos and post them here along with photos of the new ones. pictures of the pin out and any labels especially some with model numbers or wiring diagrams that may be on them would be a great help.

I don’t have any experience with multiple source lasers like yours but I think we can figure this out.

From the controller out, they work the same… the interface is the same in either case.

I can’t find this manual, but the wiring is the same for dual tubes with the Ruida and is laid out in the manuals.

The connectors are also labeled… Mine doesn’t have a CN7, CN5 to one and CN6 to the other.

  1. ensure it’s wired as specified
  2. if it’s wired right, then that resolves to a faulty configuration or controller → lps (laser power supply)

From the controller out, it should have the same… there are only 2 control wires L-On and LPWM


I have the same problem.Is there a any news?