The red light is an indication that our Soonmark printer has a problem with your label.
Most likely, it needs to re-learn your label.
Please ensure the labels are loaded correctly in the printer and then run paper calibration
following the steps below.
① Press and hold the paper FEED button on the printer.
② While pressing and holding the paper FEED button, turn on the power switch.
③ When the indicator light flashes red twice, release the button immediately,
and the paper calibration is completed.
* You need to do the calibration again every time when you change a new paper size or paper type, or the red light flashes during printing.
Click and see the video of HOW-TO.
If the label identification does not work or the red light remains, please turn off printer using the power switch on the back and then turn the unit back on and repeat the above steps.