Sculpfun S9 Laser is firing but not burning

Hi there, looking for some help. I have spent the weekend trying to fix but can not find the solution.
I was setting up the limit switches with the Sculpfun CAM500. Everything was working correctly. Did the alignment test (4 Boxes) and it burnt fine.
Everything is working as it should but suddenly I get no power from the laser. No matter what I try (engraving, Material test, old file that used to work) It is basically blank when it is finished.
It seems like it is tracing the project with the laser light and doing all the right things except actually burning the wood.
Here are the details of my current setup. I am sure it is something silly… or I have blown the laser itself :frowning:
Laser: Sculpfun S9 with added limit switches and AirAssist
Current Settings:

Grbl 1.1h [‘$’ for help]




Target buffer size found





















































Hello Jane

Question, could you open the project you are trying to run and take a full screenshot of your Lightburn window.
Additionally, please, could you also go to Edit > Device settings and take a screenshot

Hi Gil,
Please let me know if you need different windows in view

Just in case here is the motherboard

Everything looks perfect
Have you inspected your laser head and the lens

I am assuming machine goes through motions - laser fires - but there is no results correct?

Yes, we even carefully cleaned the laser head.

I ran the test again. You can see the “Test” is slightly visible. But yesterday everything was working normally.
Do you think flashing the firmware would help?

Dont really think it should be software

Try this just for sanity check
Dot Test with Angle.lbrn (46.3 KB)

Yeah, big fat nothing on that test :frowning:

@misken is our resident wizard on Sculpfun and might be able to give some ideas

However, it might be time to write to Sculpfun support to get their opinion as well

1 Like

Hardware breaks, software has bugs… If it’s working then fails, it’s likely hardware. I’m sure you know what a software bug is…

This seems to have failed overnight… indicating a hardware issue.

Having stated it’s likely a hardware issue, software doesn’t modify itself, especially firmware so unless you have a valid reason that says a firmware upgrade is required — my advise is always DON’T

Thanks for the register settings ($ variables) … Don’t see a concern there.

This would be indicative to a flaky cable, wire or connector… You can pull them out and reseat them.

Do you have a voltmeter and can you drive one?


Did you try to do the “Test” text as line instead of fill? In your fill settings, you set the interval to 0.2 which is huge for the S9 head, the optimal line width should be 0.08. So there will be much whitespace in between the lines that could make it look faint.

Anyhow, you can first do the wall test, point the laser at a white wall a few meters away and check how the beam looks like. Did you clean the lens regularly?

Next, you can do the 5V-test, connect the laser TTL connector to the 5V port. As soon as you now turn on the laser, it should fire with 100% power. Does it do that?

Of course, during all these tests, make sure to have proper eye protection.

Hi Misken, thanks for your help!
I have cleaned the laser head. Not sure how to do the 5V port test.
I should be clear when I said it suddenly stopped working, it WAS after I was tinkering with the installation and setup of the limit switches. I did a straight material test out of LS and this was the result, also there is a test I did a few days ago before the limit switch and calibration was done. It is like the speed and power are off by a lot.

BEFORE (ignore title and material I didn’t update them)


The wall-test and 5V-test are described in more detail here: Guide to mechanical adjustments and maintenance

The lens was perfectly clean? No shading whatsoever? And the black cone was also clean?

Yes, we took it off and cleaned with Alcohol and made no difference.
I feel sure I have updated a setting and written to motherboard, but I dont know which one. Its the only thing that makes sense.
Is there way to “factory reset”?

There is, you can send $RST=* in the console window once connected, this will revert all firmware settings to defaults.

But I’m not sure if it will help. Though it’s worth to try :slight_smile: