Laser fill missing fill always in the same place (see pictures)

I have a Chinese 60 watt laser (1200mm tube) The machine was purchased in April 2021 and has had very light usage.
I use the Cohesion3D Laser Board (Smoothie) and light burn software. I installed an mA Meter. I have my laser power (on machine not software) at 45 and the mA meter never goes over 20ma
Water cooling CW5000

I have have used this no more than 75 hours in total (this is a really small part of my business which I wanted to increase for Christmas)
So very little use
This has been working like a charm, no problems at all until yesterday

It seemed to be missing parts of a fill (always the same parts) and the meter at some points showed no current at all even at 20% which is what its normally run at

I have added a couple of pictures for you to look at. Not sure why but the line lasering seems ok but fill is just not working correctly

I really do not know much about electrics so if thats an issue I need to be very careful

I am not sure if this is a tube issue (hopefully not) a power issue board issue or a software issue

One of the lines on the picture did not complete due to I turned the extraction air on and it stopped the laser
I have placed the product in all different parts of the machine and the result is always the same the parts that do not get lasered are always in the same place which leads me to think this is not a tube issue as its not random, could be the board or the power supply but as its not random does that knock the power supply out of the equation?
I have put this question on a couple of forums with no real outcome that is conclusive

Looks like I may have posted here already if so please accept my apologies


I’m new to using light burn but wonder if the settings are defaulting to low power. (I think I saw they will show 5% or 10% by default) I’m used to having multiple colors on an image so I can click and select the speed and power levels of each color.

So I am assuming when you say you tried 45 on the laser power, you are showing 20ma on the analog gauge and in lightburn it shows 45% power on each color.

Then when you turned on the air fan the laser stopped altogether while it was actively burning.

My initial guess for the stopping would be an over loaded circuit. As in the outlets in the room have too much draw on the circuit. I’m in a room with a 15 amp breaker and have a larger air fan, air assist, water pump, led overhead lights, and the machine itself all running. Not to mention the main room lights and computer. I do start everything up before starting a burn, but I do not notice any flicker or pause or stopping on the machine. I also ran a separate earth ground wire out the wall and into a grounding rod like the manufacture suggests.

Looking at the pics, it looks like the white space in the letters is the same on different rows. That would lead me to think the image/text itself is not clear. Have you tried re-typing the text as a “new design” and tried it again?

You also say it is a 60w tube and in the tests it shows a 90% power. That should have cut through very easily and engraved very deep. I used about 20% power on my 40w and it was a deep engrave on wood.

I use SVG and DXF files. Could the text be a JPG and it is burning the pixel loss? If it’s in jpg, try BMP. You can use MS paint and open it and convert to bmp. You can use the flood tool to test an area to make sure it is all the same pixel color as it will flood fill clearly. If there are pixels that are slightly different In color, you will see them with flood filling instantly as it will look like a mesh instead of filling completely.

The sample pics make me think the test has hidden pixel colors that are different and maybe lightburn is selecting a default low power when getting to them. In the pic, it looks to have the white areas on the letters in the 2 bottom rows also showing on the row that IS filled above them. That makes me think lightburn is “seeing” some other colors inside the letters.

The sample % gauge and ornament look “fuzzy”. Could the mirror alignment have gotten off somehow? Or maybe the mirrors got dirty or damaged?

If it were me, I would check power draw for each item plugged in. Then check lightburn itself. I would also try another program. Like K40 Whisperer or something free. That way it could rule out lightburn altogether. Then I would check mirror conditions and alignment. Maybe it’s as simple as smoke getting something dirty. I always run with air asset on and vent fans before starting a burn. That way smoke is kept to a minimum to try and keep mirrors clear.

Hopefully someone with more experience can give some ideas to what is happening here. I am curious as to what is happening. To go from clean cuts to fuzzy and incomplete cuts the next time seems really odd.

Thank you for taking the time to reply
Yes I am a complete stump here on what to do. I am thinking even the control board maybe the issue. I have the original board it came with so I will switch that out. I will also take on board your suggestion and try another program to rule out lightburn. The mirrors are clean and the laser is aligned correctly so I can rule those out. I will let you know if I fix it or if anyone else has suggestions

thanks again

Not sure you can use K40 Whisperer with the Cohesion 3D board. Maybe try this, save your file and try scaling the size down and move to another corner of your work space on some scrap. If you get the same result, it’s the file. if it fixes the issue, it’s probably an alignment/dirty optics issue.

Ok, solved

It was the power supply
Brought one from eBay basic at £78 60watt, fitted it and all good

I also brought one from Amazon (wasn’t sure if the eBay one would turn up as the seller has a bad reputation, but it did show up before the Amazon) but not sure if this will work with my 60watt laser tube its a
Cloudray 60W CO2 Laser Power Supply 220V HY-T60 for CO2 Laser Tube T Series
Now I don’t know what a T Series Tube is and if I have one or not (my tube is about 1200mm 60watts, no info on the tube what so ever) the cost from Amazon was £160 so over double the price of the eBay one

Does anyone know if it will work and if its better?



Cloudray makes really good stuff, but if the one you have is working and is cheaper I’d stick with that and send the other one back to Amazon.

I’m glad you found the solution to this one!

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