If the red LED is not lit, check that the tool is correctly connected to your computer with the supplied USB cable.
Make sure that the USB cable is not damaged, and if possible try again using another suitable USB cable.
Use the USB cable supplied in the standard kit to connect the tool to the computer. We do not recommend using extension cords or other USB cables. In case you need to use a USB cable other than that supplied in the standard kit, make sure to use a shielded USB cable. USB cables not supplied by Alientech Srl may cause problems.