Welcome to Laser Pointer Forums - discuss green laser pointers, blue laser pointers, and all types of lasers

Help with troubleshooting 5W Laser


New member
Jan 6, 2020
I tried firing up my 445nm 5w blue laser today and it didn’t turn on. The first issue I noticed was that there was no voltage going to the driver. I had to re-solder the joint that connects the negative copper ring to the threads of the laser body. It turns out the circuit couldn’t ground itself to the negative side of the battery since the solder joints weren’t connecting to the copper ring in the flashlight circuitry that supplies the driver. I attached a picture highlighting what I’m talking about.

Now I can get 7.5V to the driver from the 2x 18650 batteries. On the output of the driver I am only getting 4-5 mV and the diode still isn’t giving out any light. Is this a normal voltage? I’m trying to diagnose whether the diode is broken or the driver is broken.

Any help is greatly appreciated!1FA7F08D-58B7-4A29-BD46-67ED753F2584.jpeg