I have the SJCAM SJ4000 and it also has a micro-USB for either power/charging, data transfer (mounts the SD Card as a drive), or to be used as a USB camera on the computer.
But..... in some modes it also will allow you to send video out on the USB if you make a special cable. You can see a video of it below. It will send out a composite signal. So it sounds as if your micro USB port on your camera may have 11 pins, you'll have to look carefully and see if they are there inside your microUSB port. If they are, then you need to buy the special 11-pin microUSB cable to access those contacts externally and get to your LED signal.
Apparently, the 11-pin micro USB is called an "MHL" cable and usually is used to go from a phone that supports it, to an HDMI to play on a big TV. That way, they don't have to insert another port on your phone (micro HDMI).... instead they use the same port for both micro USB functions and with the MHL cable you can hook it up to HDMI on your TV.
You can find info on MHL here:
https://en.wikipedia.org/wiki/Mobile_High-Definition_Link