Hi,
Since I purchased S3D, printing was always hit or miss over USB for the left nozzle. Right would work most of the time however the left might have worked 1-5% max...if ever. Frankly I can't remember the left nozzle ever printing. The software will heat up the nozzle, the bed when I select the left nozzle but not go beyond that. Printing over a SD card isn't a problem, both nozzles work more than fine.
Not sure where the communication goes buggy for the left nozzle printing but if anyone has a suggestion please let me know.
Thanks!