Tested successfully.
SM-R820 / SM-R830 USB Pinout
If Windows Device Manager detect unknown device, try again with
green and
white cable switched...
About SM-R500... Still no idea...
I found no Service Manual nor I have this device...
SM-R600... Pinout seems in Service Manual...
2 wires on left side of board... 2 wires on the other side... something like this...
Best Regards