3500mw blue laser pointer button issue

 

1. First of all, please make sure the batteries work well and    installed correctly.

Use 2 x 16340  or  2 x 18650  or 2 x 26650;

Positive to laser head;

Never use 3 batteries together;

 

 

 

2. Use a 5V USB wire test the laser head.

Remove the battery tube compartment, there is a  interface can connect the 5v USB power.
laser pointer usb interface
 

3. Tight the end cap.

 

laser pointer cap