I built an MS3X about a year and a half ago. I tested it with a 12 volt power supply and it was working fine and was able to load the firmware to it and ad a base map.I didn't get to use it last time since my miata was wreaked. I have since gotten another miata and want to put it on. I built a harness for it and everything but when I plugged the ecu to the power supply and to my computer, it wasn't detected by tuner studio or portcheck. I've tried an rs232 to USB cable and plugging it directly to USB, neither detects it. Direct USB only pops out a com port. I'm hoping it isn't broken because it did work before and i haven't really done much with it besides loading the firmware and basemap. I also used the boot jumper to see if I just had to reload the firmware but no luck either way, Still only com ports popping out.