The laser is permanently on

I have a sculpfun s9. When I turn it on, the laser diode is permanently on. What could have happened?

Sounds like a hardware failure…

You can check to see if the pwm signal is stuck high would would indicate a probably controller issue…

If it’s low, then it’s probably the laser module…

Do you have a voltmeter and can you drive it?


Can you take a picture of the laser module and the connections on the mainboard? It might have been plugged in wrong.

You gave me a third of the information I asked for…

  1. type of lps
  2. access/use a voltmeter

These are supposedly the connections… from their site.

Assuming it’s a plug and play substitute… as the video describes…

From the following about how the mg3 is wired… I’d guess one of the settings the following screenshot describes are incorrect…

Check them anyway… they are easy to get at…

There are only two control lines for an lps, besides a common ground.


Without knowing what you have for an lps along with if you can check things with a voltmeter, I can’t help much further…

Good luck


Is the MKS DLC V2.1 card compatible with my XY DLC V1.0 card?

The laser is connected correctly on your board. So, it’s not a wrong connection issue.

  1. try to reset the firmware to factory defaults: send “$RST=*” in the console window
  2. update the firmware, choose the S9 firmware available here: Firmware Update & Settings - Diode Laser Wiki
  3. As Jack pointed out, measure the TTL S pin, if it has 5V, it should have 0V if the laser is inactive.

The MKS DLC is completely compatible, you can use it as 1:1 replacement. You can also use the MKS DLC32, which is also completely compatible.

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