[header] How to charge a fitbit [title] Try a different usb port. [step] There's a chance that the usb port you are trying is malfunctioning, or isn't producing enough power to charge the tracker. This is most common with usb hubs, or older usb ports. 
Try connecting the charger to a different port to see if it works. [title] Connect the fitbit to a wall-charger instead of your computer.