# Diode laser on a LM Mk3 **URL:** \ **Category:** 🔥 Laser\ **Created:** [September 27, 2026, 7:47pm UTC](https://forum.sienci.com/t/diode-laser-on-a-lm-mk3/27169 "2026-09-27T19:47:40Z")\ **Posts on this page:** 1\ **Showing post:** 2
**Author:** ![\_Michael](https://forum.sienci.com/user_avatar/forum.sienci.com/_michael/32/2962_2.png) [@\_Michael](https://forum.sienci.com/u/_Michael)\ **Post date:** [September 28, 2026, 12:47am UTC](https://forum.sienci.com/t/diode-laser-on-a-lm-mk3/27169/2 "2026-09-28T00:47:15Z")
I wonder if it’s related to this. > [@No power at laser output connector](https://forum.sienci.com/t/no-power-at-laser-output-connector/27030/9): > > Are you running the stock firmware? Awhile back I flashed grblHAL, built with the grblHAL web builder, to my SLB on my LongMill Mk1. Everything was working fine until I needed to use my laser. I couldn’t get it working and wanted to proceed with my project so I flashed it back to sienciHAL and my laser worked again. I don’t know if I missed something in the web builder configuration or the settings somewhere in gSender but I got it working pretty quickly when I switched back. My laser is 3rd … Just to be clear I had built the firmware using Sienci’s LongMill Mk2 profile. Now there is a LM Mk3 profile on the [Web Builder](https://svn.io-engineering.com:8443/index2.html?dev=1) as well. --- _[View the full topic](https://forum.sienci.com/t/diode-laser-on-a-lm-mk3/27169)._