I have a OMTech K40+, which has the upgraded controller for LightBurn.
The laser head will move, however, the laser will not engage when you hit start. I have checked the machine settings and The “Laser Mode Enable” is checked.
Is there something else that I need to check?
I have lightburn version 1.4.01
Hello, welcome to the group…
Has it ever worked since the controller update?
How are you wired to the lps from the control board… do you have a power adjustment pot?
I bought this unit brand new from
OMTech with the upgraded controller.
It has not worked correctly from day one… If I hit the test button, it will fire, however, it will not fire using any software.
OMTech sent me a new Laser Power Supply unit to see if that was the issue…same problem
The photo is the control board
We have to know how it’s wired, maybe OMTech can help you find the information. I can’t tell anything useful from the photo you posted.
The lps has two control lines and a common ground. The control lines are pwm and laser enable.
These can be wired in multiple ways, but generally the K40 has a voltage divider (pot) to control the IN pin voltage of the lPS. This is the current limit voltage.
The Laser enable is driven by the pwm output.
There is something missing in how you wired them, since it will lase with the test button…
Back to how is it wired? Do you have a link to a video or something on how you did the upgrade?
OMTech will be sending a new motherboard, now.
OMTech is just telling me that it has a K40 Nano mothboard, at the moment.
I just ran another test using the square. I
Everything below “$32=1” is the program burning the square.
The result was movement of the Laser head but no laser burning to form the square.
Hopefully the photos below will help.
OMTech will be shipping a new K40+ to replace this one…they could not figure out what was going on.
I just received 2nd my K-40+ I ran out of patience, ordered a new one and shipped the old one back. The test button fired so the laser was working.
I had diagnosed it to a problem in the water protection circuit which is in line with the safety switches for the lid and drawer. Switches were good but the was some miswiring in the harness. I would have checked moer but as we say in Arizona, “No My Yob”
New one works out of the box. Same controller as yours.
This is quite ironic, and may help others if they have the same problem.
We bought our second k40, used, that had problems that were thought to be software problems, however, we got it home and my girlfriends older laptop would never find it (but runs our other k40 fine) we just kinda gave up for a while.
I bought her a much newer (used) laptop and we decided to dig into this k40+ a bit more. This computer finds it no problem, and we are running lightburn. The reason i logged in here is because we are having the exact problem Dave did. Using the test fire button works fine, but running a program ran everything except the laser. You could actually hold the fire button and it all worked, but never worked with the program.
All the research i have done explained that there were 2 different boards between their regular k40 and the k40+, which came with a honeycomb bed, air assist and lightburn compatible. We tried all the same fixes to no avail, so i started taking things apart.
Here is what i found! We grabbed all the parts that were originally in this machine, one of which was a blown power supply. When i compared the 2 supplies, I noticed a hot glued jumper on the old supply, but not on the one installed on the machine. I removed it from the old supply and installed it on the new one… guess what, that solved the issue. Here is the ironic part… the old power supply was in the box that the new one came in. On that box was the shipping label, that had the name Dave S##### (dont want to spell it out). I have Dave’s old machine!
Yes, this jumper solved the issue and laser working well now
