Answer: The carbon roll has become loose
To fix this do this:
(Firstly ensure the printer you are troubleshooting has only one button on the top, if it has 2 buttons it is a BP744 printer)
Open the printer by clicking the buttons on each side and tighten the front spindle, close the lid.
Go through Printer Initialisation first and then Gap Sensor Calibration.
Printer Initialisation is done by turning off the power switch, hold on the top button then turn on the power switch, release the button when LED turns green after 5 amber blinks (Any green will do during the 5 blinks).
- The LED color will be changed as following:
Amber -> red (5 blinks) -> amber (5 blinks) -> green (5 blinks) -> green/amber (5 blinks) -> red/amber (5 blinks) -> solid green
Gap/Black Mark Sensor Calibration is done by turning off the power switch, hold on the top button then turn on the power switch, release the button when LED becomes red and blinking (Any red will do during the 5 blinks).
- The LED color will be changed as following order:
Amber -> red (5 blinks) -> amber (5 blinks) -> green (5 blinks) -> green/amber (5 blinks) -> red/amber (5 blinks) -> solid green
Turn the printer back on and click the FEED button for 2 seconds then try printing a label.